You can cancel an order anytime If you are unable to serve your Customers. To do so, you can tap on the Table which you want to cancel and then delete the Order by tapping on the "Delete" icon (see screenshot below).
 
An alternative to this is to tap on the Order Board, click on the respective order slip and then tap on the delete button (trash can icon). Tap on “OK” to confirm to delete the order.
 
Unlike typical orders, please note that you cannot cancel a Table order with a request for a new dish or recipe to be served. Here, you will have to cook the new dish from the respective Appliance to complete the order.

Note: Once the order is deleted there will be waiting time before customers arrive at the Table.
However, you can Skip the wait time by using Cash.