Every request loads all tables used by AuthS3() in modules/s3/s3aaa.py
This currently includes the table 'auth_event' which is really not necessary as this only gets used as part of the user-login use case.
Ideally this should be moved to it's own class in modules/s3db/auth.py so that it is only loaded when required.
This will mean the table has to be instantiated via s3db. instead of just db.