That I readily believe, but to face a sheet is a different matter, which I believe was the application the OP intended.
You can also cut tungsten with water jets loaded with abrasives, I've seen a 2" thick block cut like that, it was quite impressive. But that won't get you a surface. You'd need to start with a sheet of the right thickness.
I've only ever used bar stock, but I imagine the same suppliers would have sheet as well though I can see a couple of arched eyebrows when you order that, plus a question or two if you are absolutely sure they have your order down accurately.
You can also cut tungsten with water jets loaded with abrasives, I've seen a 2" thick block cut like that, it was quite impressive. But that won't get you a surface. You'd need to start with a sheet of the right thickness.