When describing a small or moderate quantity of something, the antonyms for "large order" would be "small order," "modest order," or "limited order." These terms indicate a more manageable amount of items, whether it be food, office supplies, or anything else. "Scant order" or "insufficient order" can also be used to describe a very small quantity, or one that is not enough to meet a particular need. On the other hand, if you want to emphasize a very large quantity of something, you could use antonyms such as "gigantic order," "enormous order," or "massive order." The opposite of a large order will depend on the context and the intended meaning of the description.