A few years ago, the Sr. Manager on our project came into town and invited the team out to dinner (about 35 people). He asked for separate checks prior to anyone else arriving. It was quite embarrassing when the waiter came around to each of us at the end of the meal.

My point being, it's okay to ask for a group up to about 8 or 10. More than that, I would consider just keeping a copy of the check and divvying it up later.