The gn_TaskLogTable should be kept clean by the cleanup process itself which is deleting entries older than 24 hours (default).

If the table becomes very big for any reason, there may occur a timeout when the system tries to remove the entries.

In such case, delete manually all the entries older than one day using this query:

delete gn_TaskLogTable where DATEDIFF(day,gn_Time,GETDATE()) >= 1