To dream of buffet represents a situation where you expect everything to be the way you want it all the time. Assuming things should always be your way.
Negatively, it may be a sign that you expect too much.
Example: A woman dreamed of someone eating at a buffet. In waking life she had a lot of permanent changes she was demanding from her mother before ever forgiving her. She expected "all that she wanted" from her mother to ever resuming the relationship.