Is there a back room for parties in this bar?

Not that ive seen in my time working there, unless they use another room in the thwing building, such as a classroom or meeting room.

No. Only what space you see in the bar

Not a back room, but you can set up an event there and occupy a couple of the big tables. Jolly would cater the food, and it would be just for yout event.

I believe so.