wp_aiowps_events database size is Huge?!

This table currently stores the 404 event logs.

Did you at some stage have the 404 logging enabled?

You can clear this table by going to the Firewall menu -> 404 Detection tab.
You then have 2 choices as to how you can delete the 404 entries:
1) Select the entries from the list table using the checkbox and choose the “Delete” option from the bulk dropdown box.

2) You can delete all entries in one go by scrolling to the bottom of the page and clicking the “Delete all 404 event logs” button.