quite a few 相当多。
比如：Quite a few of the students were late。不少学生迟到了。
但是因为是a few，所以+可数名词

quite a little许多、相当多。=much
但是语气较much等词更加强烈，可作为加强语气的短语使用。

quite a bit 和quite a lot我不太清楚。
但是有quite a bit of和quite a lot of这个用法，不知道是不是你要的。

这两个在英语上的解释是：If you've got quite a bit of something, or quite a lot of something, you have a fairly large amount of it.其实也就是相当多，很多的意思。
比如：
George made quite a bit of money in his first business, but instead of retiring young, he went on to make quite a lot more.

If you want to learn to play the piano, you'll need to spend quite a lot of money on lessons, and spend quite a bit of time practising.

但是前者后面只能跟不可数名词，而后者后面只能跟可数名词。