Closet Datacenter Project

If I were to guess, he has a 4 pair going to his NID or phone feed and he's making all those patch panel ports active for phone. You then just patch that to the respective port you want a phone on. Done it for customers who want to be able to use any jack for voice or data.
looks pretty slick.. btw any chance theres a bathroom near that room that has an exhaust fan vent on it? you might be able to create a vent from the closet and patch it into that with a flexable hose in the attic. just remember if you ever plan to move to put it back since it most likely wouldn't pass code. and if your worried about the AC. just shove a towel into the floor/wall/roof AC vent. it will cut it off from the rest of the house. and if you want to get really crazy you can use one of those door sock things that slide under the door.
Jeff is right, its for phone. I have 3 rj45 at each drop so I can pick and choose what I want for each port.

And there is a bathroom across the hall yes, its getting much colder now so attic work is more friendly.

I know using splitters is supposed to be well usualy unwanted when doing coax stuff... but if I need multiple lines what would be the best practice? I will need 6 conections through the house that I can think of.
Home run your lines just like you do for networking. So if you need two coax in a location, run two.

Splitters aren't hugely bad if done properly however, for Cable tv and newer DirecTV installs. No idea about Dish.