Having the EXACT same issue....what do you mean by:
" will try to stop the server and see if I can access the table."
When i stop the server - I lose access to the entire database. I cannot clear this either, as it appears "in use" in moodle's mysql admin.
EDIT....i fixed it! I had to scroll to the bottom of this screen and select "empty" from the table drop-down for: ken
It now works!!!