Wow. If it is actually an ebelskiver pan from Denmark, that would be amazing, as my grandparents immigrated from Copenhagen in the early 1900's. It would be rather large, if it is that. It has seen a lot of use, porcelain is gently but evenly cracked throughout. As an egg poacher, I imagined it set in a skillet of boiling water, thus to poach the eggs. I have used poachers that set on water, egg poached within the item. That's kind of cheating, for purists, but they're out there.
Thanks for all the comments---would love something definitive, but thoughts and educated guesses are also greatly appreciated. :)