C.O.
Pearl River Bowling alley has a back room to rent and people can bowl too.
Also Grand Central in Congers has a private room and the fee per person is $22. This is cheap, restaurants usually charge $30 a person.
Fantastic caterer is World of Catering in Valley Cottage. They charge $10.50 a person. But they only cater, so you would need a place. If you know somebody in the Orangeburg Fire Dept. they have a new building and room to rent. Or if you know somebody that has a condo - you can rent the community room.