I have always referred to it as a joining table
I call BS if they "take points off" for not knowing the exact term "joint table", and if so that's not the kind of company I'd want to work for.
Sadly, looking for excuses to rationalised that the interviewer doesn't like you is still a thing.
Edit: On the other hand, asking the question in a way that gets at the concept, not the term, seems very reasonable.
I don't think it's relevant, but yes, I have interviewed at such companies.