In general (and without more context) I wouldn't call spam fake meat (maybe "processed meat product"); nor would I call tofu in and of itself fake meat.* Fake meat to me would be vegetarian "hot dogs," "hamburgers," etc. which are made from things like isolated soy protein and vital wheat gluten and are meant to resemble (as much as possible) real meat in taste and texture. They are marketed as meat substitutes for vegetarians.
*Tofu might be used to make meat substitutes but if I order fried tofu at a restaurant, that's not fake meat, that's just tofu.
I'm afraid I'm not quite sure what you mean. I don't think there is a specific word for the type of meat served in a fast food restaurant. However we have a term -- "mystery meat" -- to describe the kind of unidentifiable, processed meat often served in cafeterias.
So to me "fake meat" is a meat substitute (marketed to vegetarians) that does not contain any actual meat.
"Mystery meat," while made from actual meat, is so highly processed that the source of said meat is not readily identifiable.
I have friends who are vegetarians and they use a food product that is based on mycoproteins and can be bought under the name of chicken, fish, beef etc….but there is no meat in it. It’s like a substitute to put in meals that use meat…so you can still make chicken curry in the same way for example…but use this non-meat product instead of chicken. I’m not sure we can name products so I haven’t provided a link.
OK pour soi-disant viande (péjoratif) si on parle de « vraie » viande dans un contexte de bouffe-minute.
Quant à simili-viande, c'est un terme utilisé dans l'industrie de l'alimentation pour désigner un aliment (végétal) qui imite la texture ou le goût de la viande. Je le mentionne au cas où qqn en aurait besoin dans un contexte plus neutre.