Boot into Safe Mode, then reboot normally, and check again.
Start up your Mac in safe mode - Apple Support
Safe Mode cleans up and rebuilds various caches. (It may not clear this case.)
If the Safe Mode boot fails to resolve this, then launch Terminal.app and issue the command:
audit -e
It appears that auditing is enabled, which is common. And that the audit data is not getting cleaned up. Which is not common. (I have the expected week or so of those audit files locally, which means log rotation is working here. But is apparently not working there.) (dialabrain: sudo is your friend. Or can be your enemy. Depending on the command.)
If the deletion via the audit command fails, yes, you can sudo rm and remove those files. With care.
For details on auditing and the above command, use the command-line command:
man audit
And because your data is important, you will want to have complete and current backups before any of this. The above-listed commands are all benign, but some command mistakes can be bad (including those errors involving sudo rm), and other errors and issues are also possible. And there’s already something a little weird happening here.