I have an MS Access front-end (Oracle back-end) that has 2 linked tables, 2 MS Access queries, and 4 reports.
I've noticed that the .accdb files (stored on users' desktops) get bigger over time. They start out at under 1mb after a compact, and end up being 10-20mb after a few months use.
Why is this? There isn't any data stored in the file, so why does it get bigger over time?
It's because (some) temporary data are created in the frontend. It shouldn't matter at all, except if it disturbs you.
You can avoid that completely by making the frontend file read-only, but usually it pops a warning message when the user launch the frontend. It will force temporary data to be written to separate files.
Another method is to set the frontend to compact before closure. However, that sometimes fail, thus causing more trouble than advantages.
The definitive method to avoid it, is to copy a fresh frontend to user. The user clicks a shortcut to a script that copies the file from the server to a local folder and launch it from the local copy. A script to handle that can be found here:
Deploy and update a Microsoft Access application in a Citrix environment