What coil-like components are these?
These are common-mode chokes. They're 2 inductors which are magnetically coupled.



Yes, that makes them a transformer as well !
And you could use them as a transformer. But they're only 1:1 transformers so that limits the applications.

These are used to block high-frequency (common mode) signals from getting to the mains connection for example. You see them mainly in switcher mode mains power supplies