Can you do something about this spam blizz?

We're unable to prevent other players from contacting you, Hitu. We can only investigate and take appropriate actions if such contact is against our Terms of Use and is reported to us. What you listed doesn't appear to violate any of our policies though and is simply 4 different people attempting to invite you into their guild around the same time.

You can block the invites themselves, but for any other preemptive blocking, you'll need to look to an addon, as Palaurus suggested.