Definitely was designed to hold something that you'd want to stay far away from. Like something hot, or something like a railroad spike that was going to be driven in.
Google "circle to search" says blacksmith tongs.
It's likely a blacksmith tongs, but it may have doubled as a medieval torture device. Maybe it was used for tongue pulling??? It sounds bad, but is probably less painful than the chevalet...
I'd assumed it was for holding a rail spike while driving it in, but a blacksmith's tool seems to come up more often. And the rail spike tongs that I've found online look different.