If during the course of the day something happens and either one of your customers or employees damage any inventory, you can declare this via the "Damage" button (only employees with the right to declare damages are able to do so). Here a visual guide:
First choose the table and tap on "Pay"
In the next step choose "Damage" (red square in this picture). Important: If the button is pressed the payment process will be finished!
In the pop-up you can enter the number of customers on the chosen table: