The table service restaurants aren't set up to do take out orders. LeCellier is often very busy and the kitchen would back up even more if they allow to go orders. Perhaps it was done in the past or at very slow times, but I wouldn't count on it anymore. However, you could make a reservation, be seated, then when your order comes, ask to have it put into containers.
Via Napoli had a take out window selling pizza by the slice during the holiday season, but I believe it has closed.