The Sterkarms would not have served their meals as 'starters', 'mains' and 'dessert', as we do.
Nor would they have served sweet and savoury dishes as separate courses.
I've talked about 'starters', 'mains' and 'puddings' because that's what we're familiar with but separate courses only came into fashion hundreds of years later.
The Sterkarms would have followed the medieval custom of putting everything on the table at once -- fish, meat, savoury, sweet, it made no difference. Everyone would have served themselves, or been served, with whatever they wanted.
At a great feast there might have been several 'removes' -- that is, the first array of dishes would have been removed, and replaced with another array of equally mixed dishes. This was about status. Obviously, the more times you could 'remove' an assortment of dishes and replace them with another assortment, then the wealthier you were.
(Perhaps Isobel Sterkarm serves her 21st Century guests their meal as 'starter, main, pudding' because Andrea has told her that is the way the 'Elves' do it. Isobel would try to please her guests and make them feel comfortable.)
Between courses, the guests would have been provided with water and a towel, so they could wash and dry their hands. This was because people used their hands to eat with quite a lot. Forks were still unknown in Britain. People ate with a knife, a spoon and their fingers.
Almost everyone carried their own knife with them, at their belt. Some carried a spoon too, though Isobel Sterkarm would probably have provided both knife and spoon, to show how well-equipped her household was.
For the same reason, she provides her guests with plates -- though when alone, the Sterkarms probably still ate from trenchers, or large, thick slices of stale bread.
Films sometimes show people in the past merrily throwing bones and unwanted food over their shoulders, to show how 'primitive' and 'uncivilised' they are. It should be noted that, despite the Sterkarms' rough and ready ways, Isobel would be very insulted if any of her guests threw bones or unwanted food on her floor. The modern idea that the households of five hundred years ago were absolutely filthy is not accurate. People kept their houses, their clothes and themselves as clean as they were able to do.
Isobel would have set her maids to sweeping the floors reguarly. Freshly cut reeds would have been spread over them, if available. If not, then straw would have been laid down, perhaps mixed with scented herbs.