Why does my iPad Pro (M4) restart when using Microsoft Office apps?

Of you are experiencing difficulties with a specific App, delete the App from your iPad:

Remove or delete apps from iPad - Apple Support

After deleting the offending App, perform a forced-restart of your iPad;

Force restart iPad (models with Face ID or with Touch ID in the top button)

If your iPad doesn’t have the Home button, do the following:

1. Press and quickly release the volume button nearest to the top button.
2. Press and quickly release the volume button farthest from the top button.
3. Press and hold the top button.
4. When the Apple logo appears, release the top button.

Force restart iPad (models with the Home button)

Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.

Finally, you can re-install the App from the App Store.