My wife and I have been to OTTO several times. It is owned by celebrity chef Mario Batali. It is fun and casual and I 'm sure that they can accommodate a large group such as ours. I can even call and inquire but it is very important that I know the confirmed number of attendees.
OTTO Enoteca Pizzeria
New York City, New York
Serving classic Italian pizzas, a large selection of house-cured meats, Italian and local cheeses, Artisanal Gelato, and boasting a 750+ all-Italian wine list, OTTO has become a destination for New York diners as well as a neighborhood hot spot...
http://www.mariobatali.com/restaurants_otto.cfm