OneDrive - Personal deleting Sims 4 files.

LilliPeterman​  The zoneObjects files are temp files that the game normally deletes when you quit.  They're being saved because while they exist, they're stored in the Sims 4 user folder in Documents, which OneDrive is syncing.  So you can safely delete all of them, or really anything that's in ... The Sims 4 > scratch as long as you don't have the game open at the time.

If you want to deal with OneDrive on a more permanent basis, this guide covers several options:

[CURRENT ISSUE] Sims 4 saves/user content disappearing (PC) | EA Forums - 11838402

Not all options show up for everyone, so if you don't see one of them, move on to something else.  And feel free to ask more questions about these settings.

Wildstripe​  If you want to deal with OneDrive as well, that guide may help you too.