Block visa??? I guess you mean like group visa, for several persons working for the same company.

I have not heard something like that.

On the other hand all companies in qatar are "given" a quota for visas depending on nationalities hired and having a balance between nationals and non nationals, and also some countries will have a certain preference.

In the end better to check with immigration authorities about the capability of the company to get several visas at the same time.

Regards!!