조금 means "a little, a few, a bit, slightly"
It can be used before adverb or adjective.
조금 많은 편이에요 is humble expression of 많다
e.g.
친구가 조금 많은 편이에요.
I have friends a few too much, I suppose.
I have a lot of friends, I think.
그 차는 조금 오래 됐어요
It is a bit old car.