A banquet camera is a type of large format camera used in the early 20th century for photographing large groups of people in formal occasions.
[1] The film format of banquet cameras were of narrow aspect ratio, with formats of 7x17 in.
The large, wide negatives were ideal for fitting everyone around a table in a recognizable way.
Their use died out as enlarging smaller formats became more popular [1], wide angle lens use increased, and the snapshot aesthetic became acceptable to record even highly formal events.
[2] While a few photographers today use banquet cameras for their original purpose, their most common use today is for landscape or architectural photography.