Assign a menu card to the TR event to limit the range of items that can be booked for individual reservations. (Creating a food or drinks menu).
Go to the second tab Added fields of the TR event.
Select an existing Menu card in the top line by clicking the expand triangle next to Only items from menu card, or create a new menu. If a menu card has been assigned, only the items listed there are offered for booking in reservations. It is not possible to assign multiple menu cards.