Looks like it could hang from a hook, saving floor space. Also looks like maybe a funnel for watering.

Alternatively, one can grow them in a pot. They like sun. Just poke the stumps in good soil, and water as needed. If you live where winter is cold, a sunny window would probably work.

Edit to caution: Don’t grow indoors if you have a cat. Onions are toxic to pets and you can’t keep it out of their reach, like you could with a dog.