Is it possible to enlarge the contents of a PDF?

If you have adobe acrobat pro, you can use the following steps to resize and crop multiple pages of a PDF more 

efficiency : 

1. Open your PDF document in Adobe Acrobat Pro.
2. Go to the "Tools" menu and select "Edit PDF."
3. In the right-hand pane, click on the "Edit" button to enter the editing mode.
4. Select the first page you want to resize and crop by clicking on it.
5. Go to the "Format" panel on the right-hand side and click on the "Set Page Boxes" button.
6. In the "Set Page Boxes" dialog box, adjust the values for the "Width" and "Height" to the desired size (5.5" x 8.5") and click "OK."
7. Repeat steps 4-6 for each page you want to resize and crop. 
8. Once you have adjusted all the pages, go to the "File" menu and select "Save" to save the changes.

By using this method, you can resize and crop multiple pages simultaneously without having to import them into InDesign individually. It allows for a more efficient workflow when working with a large number of pages in a PDF document.

If you are on Windows, you will still have the Adobe PDF print driver. You can print to it from Acrobat by changing the scale to 106%. This will change the content but not the original page size.

If you want to make the page size larger, you can use the Adjust Page Size options under the prepress tools.

If you want to make the page size smaller, you can use the Crop tool. Then you can "sanitize" the document to remove any hidden text if necessary.

In InDesign, you can use the place multi-page PDF script, print to the 106% size, crop in Acrobat.