A logbook for your actual photo and video files — which hard disk, whether it's backed up, whether it's been delivered. Not about anything inside TaKo Studio itself.
Go to Data Storage and click Add record. Fill in:
Search by client, event, or disk number, and filter by delivery status (Delivered / Not delivered) or backup status (Has second copy / No second copy) — a fast way to answer "where's the footage for this wedding" or "did we ever back this one up" months after the shoot.