Manage you booking during service, by setting booking status.
You can find all these functions in the lower left corner of Day View. The functions can also be accessed by option clicking (right mouse-button) on the desired booking.

Arrived: The guests have arrived in the restaurant, but not seated at the table yet. Perhaps they are having a drink in bar, or waiting for the rest of the table
Seated: The guests are seated at the table
Check out: The guests have left the table, and the table is now available for new bookings
Reset seated: The guests are still at the table, and should not have been checked out
Set confirmed: The guests have confirmed their booking
No show: The guests has not turned up for their booking. Marking the booking No show, will add info to the Guest History, and make the table available for new bookings.
Fast status
The status can also be set by clicking directly in the arrived or seated column

