All Office application display the menus, ribbons, sidebars as way too large.
It is not an issue where going to Settings->Display->Scale & Layout, setting to 100% will fix it. I already have that set. I have also toggled the 'When using multiple displays options' several times within Office applications settings.
Everything else is just great with my display. All text within the viewing panes of Office applications is fine. For instance, in Outlook, the ribbon is huge, the sidebar is huge, I can only see about 4 emails at a time listed. However, where it displays a full email on the right, that text is just fine. If I lower the zoom level it gets too small to read. Also that zoom level does not affect the size of the ribbon or side bar. Same issue in Excel. Ribbon is huge, but the cells of the spreadsheet are normal size.
The file explorer menus and ribbon also display fine. All other non-office applications display fine.
It was working fine. I must have pressed some button inadvertently which increased the size of these items. Or maybe it was because I temporarily hooked my laptop up to a different monitor.