I want to be able to pick numbers out of my contacts to put right to voicemail. Does this do that?

That doesn’t really fall under an intended use, but you could always use manual entry to lookup any number you want, even if it’s in your contacts. Then from the results screen just hit block.

However, depending on which manufacturer skin your phone has, you might be able to block numbers just by editing the contact and checking the “send to voicemail” option on.