From the Super Mario Wiki
Table Tennis is a class of events from Mario & Sonic at the Olympic Games and Mario & Sonic at the London 2012 Olympic Games which includes all events that involve using a paddle to hit a ball back and forth between characters. This is one of the many classes that have only one event in them. This event takes place in the Peking University Gymnasium (Excel London in the London 2012 Olympic Games). In Mario and Sonic at the London 2012 Olympic Games, the rival for this event is Dry Bones.