“What is this spherical silver item that opens up to reveal a fixed metal plate with small holes in it?”
Answer: “This is an English muffin dish — you fill the bottom with hot water and have a fire underneath to keep it hot, and the muffins go in the top and the steam keeps them hot and delicious.”
Corn Remover. Cut the kernels from the cob.
It's for both. Also good for squeezing citrus, cracking eggshells, and breaking bones. Not everything has ONE purpose.
It's both, and good on crab... although with lots of crab/lobster consumed a person gets good enough not to need anything but teeth.