Originally Posted by Mountain Trader

You might consider Le Square Trousseau:
http://www.squaretrousseau.com/

This isn't the greatest place in Paris, but it is pretty good for the price. They have main courses for around 20 euros such as Parmentier Royal (with confit de canard) and veal cutlets in creme sauce with mushrooms.

They also have a private room next door to the restaurant (which has it's own window out to the street) which would seat your group comfortably. I have no idea on what terms they use the private room.

When I was there (at the restaurant) on a Saturday night it got pretty hectic after 9pm when the place filled up, and service slowed down a lot. If you had a dedicated waiter/waitress, that would solve that issue but I can't advise anymore.

The locale is maybe a half mile from Place Bastille in a bustling neighborhood with a lot of commerce for regular Parisiennes.