It's a question, so it needs a question mark at the end, and it means 'Is it possible for me to put a metal container into another metal container?'. It's not a useful sentence, of course. It's just something that was invented to show that the word 'can' has three different uses - as a modal verb indicating ability, as a noun referring to a metal container, and as a transitive verb meaning to put something into such a container.

There is even this one : can a can can-can. Meaning, is it possible (can) for a bottle (a can) to danse can-can (a french sexy dance where you throw legs in the air).

it's tongue twister

Despite all the answers, it is a nonsense statement. Canning a can has no meaning. No one would ever say this sentence. Why are you asking about it?

Nice sentence playing with words! The first "can" means "able to", or "He is able to can a can." The second "can" is defined: Slang . to throw (something) away. The third "can" refers a container for storing food, rubbish, etc