Hi There,
I would suggest to open TAC case if something needs to be deleted from database tables.
You can try these though.
1: Navigate to System>tools>purge and purge the user entries.
That would purge all of the user entries if you are ok with that.
2: Restart following process on FMC via CLI
sudo pmtool restartbyid SFDataCorrelator
sudo pmtool restartbyid SFTop10Cacher
Hope it helps,
Yogesh