Only issue we've had with space on the 3900 is with my wife and I moving around in the galley - it is tight - really meant for 1 person. Otherwise there is plenty of space.

I think you can even fit 6 inside to eat and they easily fit outside. Inside might be a little tight, but doable.

If you want to see more of the space, check out their 360 degree tour.

https://www.moorings.com/yachts/sail-fleet/catamarans/3900-3-cabin