Maybe it is commonplace, but i have never seen one before.
Ornate Rogers & Co quadruple plate footed with large handle, 3 large curved claws that open/close when thumbscrew underneath is turned. Patented 1891 Important enough to engrave a large monogram in centre.
i’m guessing it’s to hold/carry something hot and round (bowl, lamp…?)
And it needs a cleaning
(apologies for the fuzzy pic, but you get the idea)