Comments and special requests for dining reservations are registered as comments.
When you view the comments for a dining reservation, you also see the comments that have been registered to the related source records, such as the corresponding activity reservation and activity. This way there is no need to move comments between sources, and this ensures that comments are not overlooked because they were registered to the "wrong" source.
See also
Attributes and Dining Preferences
How to: Manage the Dining Reservation Desk