to name just a few 与to name but a few的区别

基本上意思相同，都是在列出若干实例后说“这仅仅例举一小部分”，要说区别to name but a few 似乎比 to name just a few 的范围更广。例如：

I like fruits, apple, banana, pear, to name just a few.
Fruits are produced in China, apple, banana, pear, to name but a few.

实际区别不大，视你讲话时的立场而定。

大概意思：

to name just a few:
仅举几例

to name but a few:
还有很多，这里就不一一列举了

but = just
but 比较正式
仅此而已……