A lot of invalid blocks in pool

[Law1iet]

Hello!
I don't found any topic for newbie question, so, I ask here.

> Est. Shares   1036 (done: 252.99%)
> Pool Valid   2621
> Your Valid   34
> Pool Invalid   4768 (64.53%)
> Your Invalid   0 (0%)

What does it means? Some kind of spam for a pool? I have to go to such a pool?