Karennina,
yes you can walk in and pay for breakfast or any meals if you are not staying there , breakfast buffet is excellent , almost always 2 or 3 hot dishes as well included in the price as many cups of tea / coffee you wish , beware the baked beans are horrid more like big butter beans in tomatoe sauce, i cant remember the cost sorry, its very reasonable , clients in the roof top apartments [ self catering ] of the hotel and some locals pop in there often .