Hi John,
I've had a quick look and these are the things I found:
Report Builder - to email scheduled reports
Totara Messages - to periodically delete old alerts/tasks
Course completion - to update completion records
Competency - to aggregate competency proficiencies
Reminder - to send reminder emails
Other than that there's all the usual Moodle cron activities, but the list above covers what we've added in Totara.
Simon