The Banquet Room consists of Civic A plus Civic B plus Civic Room C. If you are looking for any of these rooms and you see that there is an event in the Banquet Room, that means that Civic Rooms A, B and C are all booked.
Likewise, if you are looking for the Banquet Room and see that Civic Rooms A, B, or Civic C have events,
then that means the Banquet Room is unavailable.