In our old home, the dining room had 7 doors - we closed off one of the doors since there were two that went into the kitchen. The kitchen also had seven doors, but we closed off two - the duplicate to the dining room, and another to a side porch (which was also accessible from the dining room). These were original, probably the same as yours! But I agree that they make it difficult to furnish a room, and for traffic flow.

So... is it possible to close off any of these doors? (e.g. does there need to be hallway access to this room?) I wouldn't close off a window if it's the only one. Sorry, that's all I can think of.

first, how cool! i always love the character of old houses. it looks like the prior owners had some bold style ideas!

anyhow, what do you want for the room? It strike me as basically a mudroom, but if you don't enter the house from that door that isn't what you want. otherwise, maybe a dining room with a table and some open shelving on the walls.

I'm not a designer, but looking at the pics
unless your house is well sealed, this room
has a LOT of air infiltration.
I see by the steam radiatiors that you are not
from my area!
But if you are going to make this room/house comfortable
you should have a blower door test. It would also benefit
the whole house.
while no one wants to be uncomfortable in thier home,
you don't know how much air is moving through the house
unless you test.
caulking would be a material cheap investment, but
working the caulk gun would take time. it is not rocket science
air sealing has a quick payback and is the easiest way
to improve comfort.
drop me an email if you want more info, I don't always
come remodel forum. I'll advise you here, but would
need to know that it would be worth my/your time to
do the whole q/a thing.
what is your location...not that I'm wanting to test your
house. The radiators tell me that it is too_cold where you live! LOL! And I work where I live.

Happy Mardi Gras,
and best of luck

Can you post a floorplan (even if it's just a hand-drawn sketch)? Seeing what this room is adjacent to (i.e. where the doors go) would be very helpful.

Can you describe it in words this way -
Wall A has doors 1, 2, and 3. Door 1 goes here, Door 2 goes there.
Moving right, wall B has ... etc.

Tell us which doors go up or down, and which have duplicates elsewhere.

And what do you want to do with the space? Is it simply visually annoying to look at all the doors? (My kid has a door poster that looks like a pony is looking out of a stall. You could have several!) Or you could put a fancy curtain over one wall, adding insulation without permanently blocking.