Reservations are not required to attend an event. Three factors determine the availability of an unreserved and available table.
Floor plan-- Not every event has tables for seating. Some events employ an open floor plan.
Demand-- Some events will sell out and there may not be any tables left unreserved.
Timing-- Some events may have few reserved tables and thus many tables left unreserved and available. If you arrive later expecting to get one of these tables, you may find that they have all been taken.
If you are serious about ensuring a table seat, then we encourage you to make a reservation. Getting here early is the next best way.