How do I ensure bottom alignment for documents with tables? Row alignment?

Hi @dublove, here is a script that vertically justifies each frame by adding space before and after each table. Is that what you need?

- Mark

/**
 * @file Justify By Spacing Tables.js
 *
 * Usage:
 *   1. Select some text or text frame(s).
 *   2. Run script.
 *
 * Will attempt to add space, before and after, to each table
 * so that the text frame(s) are vertically justified.
 *
 * @author m1b
 * @version 2024-12-20
 * @discussion https://community.adobe.com/t5/indesign-discussions/how-do-i-ensure-bottom-alignment-for-documents-with-tables-row-alignment/m-p/15048920
 */
function main() {

    app.scriptPreferences.measurementUnit = MeasurementUnits.POINTS;

    var doc = app.activeDocument,
        selectedTables = getTables(doc.selection);

    // get textFrames
    var frames = [],
        already = {};

    for (var i = 0; i < selectedTables.length; i++) {
        var frame = selectedTables[i].parent;
        if (!already[frame.id]) {
            frames.push(frame);
            already[frame.id] = true;
        }
    }

    // process each text frame
    for (var i = 0; i < frames.length; i++) {

        var frame = frames[i],
            lineCount = frame.lines.length,
            tables = frame.tables,
            firstSpace = tables[0].spaceBefore,
            space = 0;

        // calculate the excess space
        while (frame.lines.length === lineCount)
            tables[0].spaceBefore += 3;

        while (frame.lines.length !== lineCount)
            tables[0].spaceBefore -= 0.5;

        // measure space
        space = tables[0].spaceBefore - firstSpace;

        // reset
        tables[0].spaceBefore = firstSpace;

        // space out tables evenly
        var spacingAmount = space / (tables.length * 2);

        for (var j = 0; j < tables.length; j++) {
            tables[j].spaceBefore += spacingAmount;
            tables[j].spaceAfter += spacingAmount;
        }

    }

};
app.doScript(main, ScriptLanguage.JAVASCRIPT, undefined, UndoModes.ENTIRE_SCRIPT, 'Justify By Spacing Tables');

/**
 * Get tables from `items`.
 * @author m1b
 * @version 2024-12-20
 *
 * Finds tables inside different objects,
 * eg. selection, page, text frame, story.
 * Supply a filter function to narrow down
 * the table(s) even more.
 *
 * @param {Document|Page|PageItem|TextFrame|Cell|Text} items - item, collection or array to get tables from
 * @param {Boolean} [onlyFirst] - only return the first table found
 * @param {Function} [filter] - only match tables that pass this filter function
 * @param {Array[Table]} [found] - results (private argument for recursive calls)
 * @returns {Array[Table]} - the found table(s) * if onlyFirst flag then can be {Table}
 */
function getTables(items, onlyFirst, filter, found) {

    // sanity
    if (items == undefined)
        return [];

    if (found == undefined)
        found = [];

    else if (
        onlyFirst
        && found.constructor.name == 'Table'
    )
        // immediately return the table
        return found;

    if (!items.hasOwnProperty('0'))
        // put in array to process
        items = [items];

    for (var i = 0; i < items.length; i++) {

        var item = items[i];

        if (item.constructor.name == 'Table') {

            if (
                filter == undefined
                || filter(item) === true
            ) {

                // item is a table
                if (onlyFirst)
                    return item;

                else
                    found.push(item);

            }
        }

        else if (item.constructor.name == 'TextFrame') {

            var textFrameTables = item.tables.everyItem().getElements();

            if (
                item.hasOwnProperty('textFrames')
                && item.textFrames.length > 0
            )
                // check in anchored text frames
                textFrameTables = textFrameTables.concat(getTables(item.textFrames, onlyFirst, filter));

            found = found.concat(textFrameTables);

        }

        else if (
            item.hasOwnProperty('tables')
            && item.tables.length > 0
        )
            // item contains tables
            found = found.concat(getTables(item.tables, onlyFirst, filter));

        else if (
            item.hasOwnProperty('parent')
            && item.parent.constructor.name == 'Cell'
        )
            // parent is a table cell
            found = found.concat(getTables(item.parent.parent, onlyFirst, filter));

        else if (
            item.hasOwnProperty('paragraphs')
            && item.paragraphs.length > 0
            && item.paragraphs[0] !== item
        )
            // is in a story, which may contain tables
            found = found.concat(getTables(item.paragraphs, onlyFirst, filter));

        else if (
            item.hasOwnProperty('parentTextFrames')
            && item.parentTextFrames.length > 0
        )
            // is in a story, which may contain tables
            found = found.concat(getTables(item.parentTextFrames, onlyFirst, filter));

        else if (
            item.hasOwnProperty('parentStory')
        )
            // is in a story, which may contain tables
            found = found.concat(getTables(item.parentStory, onlyFirst, filter));

        else if (
            item.hasOwnProperty('pageItems')
            && item.pageItems.length > 0
        )
            // contains page items, which may be tables
            found = found.concat(getTables(item.pageItems, onlyFirst, filter));

        else if (
            item.hasOwnProperty('parent')
            && item.parent.constructor.name != 'Document'
            && item.parent.constructor.name != 'Spread'
        )
            // has a parent which might be a table
            found = found.concat(getTables(item.parent, onlyFirst, filter));

    }

    return found;

};

You have to make all vertical (line space/leading/cell height/table spacing) elements some value that always adds up to your total text frame height, so that no matter how you mix text and tables, they have the same total height.

Things to adjust to meet this common spacing include:

• Body text leading plus any space before or after
• Table cell text height plus cell margins top and bottom
• Table space before and space after

....and this will have to be continued for things like list items (bullet or numbered), headings and other content elements.

There is no simple, automated feature that can do more than help with this; it's an art and requires careful planning and meticulous adjustment of all the styles. And then you will have to accommodate variations such as 2-line table cells.

Look at it as a vertical grid, and make every element fit a vertical grid space. There's no real shortcut to that.