Most of the food at those massive meals was not actually totally consumed at table. Tatsted is more like it. If the King was there, after he finished what he wanted and his plate removed, EVERYONE'S plate was removed. Many people actually ate before coming to dinner, otherwise they might go hungry. Most of the food was not wasted, however, as the servants got the left overs. And those houses required a lot of staff. There own meals were usually rather meager, considering how much work they did.
There are not a few books on this subject but a recent one, EATING WITH EMPERORS by Jake Smith is the lateest and very entertaining as well as informative. At least, so far. I have not finished reading it.