Trying to replicate a Medieval Feast can be quite a challenge. Medieval Feasts were often very expensive affairs and grand displays of conspicuous consumption. When I design a feast I must take into consideration a modest budget, and make the most of it that I can. I also take into consideration some of the most prevalent food restrictions.
A typical course that I create will feature six dishes. Of these six dishes, I prefer to have two meat dishes, two (ovo-lacto) vegetarian dishes, and two vegan dishes. I find this basic menu design takes care of 90% of the food restrictions that I have encountered. I also provide a full ingredient list on the menus that are distributed to the feast attendees, so they may make a final decision. I do not anticipate that each dish will be enjoyed by everyone, nor that a single person will enjoy every dish. Portion sizes may be dependent upon how much time scheduled between courses.