How to translate 食客 into English?
I believe you are talking about 食客/门客 in the ancient Spring and Autumn and the Warring States Periods. Sponger maybe more accurate than parasite.
But you have missunderstanding about them. They are not honoured guests, their relationship is more like master and indentured worker which means you provider me with what I want, and I will pay back for you when you need. Basicly level, you provider me with food, I will do basic work when you need as to do some basic work for you(though some masters don't need it and just provider free food for nothing). Second one, you provider me with good life and I just pay my life for you. Best one, you provider me with everything I want and I will do what I can to help you by intellectual or asassinate the rival when you are in great danger or oppotunities.

Some one translate to hanger-on, or retainer, but realy these words can't identify their property. 食客 has the meaning of pay back, they are not just only an attendant. There is no contract to limit them with masters.