口味很重 means someone like eating something very hot or very salty or very weird, for example, if u see ur friend eating a bug, u can say: 你口味 很/真 重.
This expression can be used for other cases too. for example, ur ex-girlfriend is kind of weird, i see her photo, and i can say: "你口味 很/真 重." to you. why do i say this? maybe because ur ex-girlfriend is too ugly, maybe she is too fat, maybe she is too thin, maybe she is too old, maybe she is too much make-up etc.....anyway, i say this because i think she has one or more weird characteristics. just like u like eating something weird.....
so if someone does something weird or likes something weird, u can say: 你口味 真/很 重。
ATTENTION: u can say this to ur best friend but do NOT say it to other people. if u say this to other people, they will think u r rude or even be angry.