It depends on the context and on the dialect of English the question is using. In US English, <em>quite </em>is only an intensifier -- it can only mean "very, really". But in UK English, and perhaps in other English dialects that have kept closer links to UK English, <em>quite </em>may be a minimalizer -- it can mean "somewhat, not so much" in many contexts.

(I say "many contexts" because I think sometimes UK English can use <em>quite </em>as "really, very". It depends on the context.)

In this case, "quite" means the same thing as "very".

"Is he very smart?"

It is asking if he is above average.