My basic logic is confused: how to compare the row 1 with row2.

There was a couple of mistakes ... This line:

if(table.rows[0].cells[i].contents==table.rows[1].cell[i].contents){

should better be this:

if (table.columns[i].cells[0].contents == table.columns[i].cells[1].contents) {

1. You are looping over the columns, not the rows.

2. The column index changes with the loop var i (not the cell index)

You could code it something like this:

var sameRow = true;

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

    if (table.columns[i].cells[0].contents != table.columns[i].cells[1].contents) {
        sameRow = false;
        break;
    }

}

if (sameRow == true) {
    table.rows[0].remove();
}

This switches "sameRow" to false if any cell doesn't match. This seems easier to me, but there are many many ways to do it.

For your extra learning, I would definitely try to make a function of it, too:

// call the function
if (isSameRowContents(table.rows[0], table.rows[1])) {
    // remove the double row
    table.rows[0].remove();
}


/**
 * Returns true when the two rows have matching contents.
 * @9397041 {Row} row1 - a table row.
 * @9397041 {Row} row2 - a table row.
 * @Returns {Boolean}
 */
function isSameRowContents(row1, row2) {

    var cellCount = Math.min(row1.cells.length, row2.cells.length);

    for (var i = 0; i < cellCount; i++) {
        if (row1.cells[i].contents != row2.cells[i].contents) {
            return false;
        }
    }

    return true;

};

Don't be discouraged, I am pleased that you are trying so hard. Keep it up!

- Mark

To avoid problems like this - you should "mark" rows like this - added during 1st processing - in case that they could / should be removed at some point - then remove them first before doing any updates / extra processing. 

You can "mark" Table / Column / Row / Cell - and other objects in InDesign - using label property - or you can use insertLabel and then extractLabel to check the value.