There are 5 basic statuses, which work automatically after different actions are done:
Available – no fill. A table is free, but maybe it has been reserved or someone from the waitlist is waiting for that table.
Seated – red fill. The table is occupied.
Assigned – blue fill. A guest was called and has been told that the table just became available for him.
Reserved – gray fill. The table is reserved.
There are additional table statuses, as well, which need to be set up in the admin panel in the reservations tab; but a table will become available for any type of guest, whether a party is from the waitlist or walked in -- it will still work.
Keep your status!:)