You may wish to assign to seats only those guests who have accepted your invitation.
Select Edit|Preferences. The Preferences window will be displayed.
Select Accepted in the Allow seat assignment with RSVP drop-down menu.
Click OK.
If you have unaccepted guests assigned you will have the option to unassign them. Click Unassign.
If you have unassigned guests select File|
Automatic layout. Only guests who have accepted will be
assigned to seats.
Next: Arrange multiple seatings for an event>>