Pages not working since last update

My Pages v14.3 on Sequoia v15.3.1 works just fine, so I suspect that you may have added some third-party software that is interfering with your version of Pages, or you are attempting to use an outdated version of Pages. It is not the operating system or I would have issues too.

1. Verify that you have Pages v14.3 installed. If not, correct that via the Mac App Store.
2. Boot your iMac 24 into Safe Boot mode: Start up your Mac in safe mode - Apple Support
   1. This will clear the System cache, and rebuild the font and other databases.
   2. Does Pages v14.3 misbehave while in Safe Boot mode?
   3. Reboot normally, and determine what if any Pages issues persist.
3. Press and hold the shift key while launching Pages to prevent it from loading its last saved execution state.
   1. Determine if Pages v14.3 now works correctly.

I have no issue copying and pasting a Pages table across pages or sections in a standard word-processing or page layout document — whether by standard copy/paste or by pressing the option key and (duplicating) dragging the table elsewhere. Thus, I see no issue that needs to be fixed, unless you do have third-party software (e.g. anti-virus) that is intruding into normal Pages behavior.

Pages v13.2 was for an early release of macOS Ventura. It is not intended for macOS Sequoia v15.3.1.

The current Pages in the Mac App Store is v14.3 and requires macOS 14.0 or later.