Split a one-page PDF into several Pages (NOT separate documents/files)

You can create copies of all the page you want to split, and then use the crop tool to select just the area you want to have on page 1, then the same for page 2 and so on. I've created a script that splits a page into two or three pages, you can use that idea to create more target pages:

Page Splitter - For The 3rd Time - Splitting Tri-Fold Brochures - KHKonsulting LLC

Assuming you do not have the source document to recompose, there is a way to do this, but it renders a PDF that is image based.  This may, or may not be acceptable for your usage.

1. With the PDF open, Edit> Take a Snapshot.
2. Draw a box around what you'd want as your 1st page.
3. Go to the Pages Panel, and click the option button> Insert Pages > From Clipboard... after last page.  There's your new 1st page.
4. Repeat as desired/needed.
5. Once you all the new pages, delete the initial one that's too big.

Not ideal, but it will work.

I hope this is helpful.

Dave

The easiest way would be to create a multipage InDesign file, set up as spread pages, (un-check Allow Document pages to Shuffle so the pages will stay together), then place your tall PDF into the pages. Rotate it so it spans across the pages, then export to a new, multipage PDF. You can rotate the single pages in Acrobat.