The largest dome has a diameter of approximately 9.45 metres (31 feet) making it 70,1 metre2 and it can contain approximately 100-120 people standing and 70 people tabled. Of course it can fit more people standing or seated when it’s arched open or when all 3 Domes are linked together. See the following example of a dinner for 90 people:

Tent-PropBasic 

The round tables have a diameter of 1.8 metres (according to Boels.com enough to seat 10 people at) The width of the chairs are 0.445 metres.