When I spoke to the staff at Montpelier, they also suggested this event for our group. It is a pub night to benefit Montpelier. It will include live music, staff in 18th century costumes, old fashioned Tavern Games and hearty specials.
Rather than try to reserve a block of tables for our group, I thought it easier for us to just grab spots and/or put in smaller reservations as we enter.
We are not charging for this event. I imagine that Sullivan's would like you to purchase something even if is just an appetizer or beverage.