It is not bigger than a bread box

Was it something that could be split or was it given whole to each person?

It was handed whole to each person and returned whole

Were they using it for him?

Yes. He was very temporarily loaning the item and they did him a favor.

Was it expensive?

Some are cheap while others are very expensive. People choose according to their interest and ability

This one is not as easy as the others. I'll try to think of a hint that will make things click for you.

Is it a collectible? Does it have a very specific use? Does it click?

Was the man valet parking his car?

A collectible? No. A specific use? Yes! Does it click? I think most do but these days you can disable the noise. No cars are involved, but good try.

I think it sounds like a cell phone.

Sounds that way to me too oldbroad, but why would you be frequently handing strangers your phone?
Unless maybe on vacation to take pictures of you?

Because you don't know how to work the darn thing (like me). What made me think this:

"Some are cheap while others are very expensive. People choose according to their interest and ability smile"

Together with this:

"He was very temporarily loaning the item and they did him a favor."

Jimbo got it! Any camera or cell phone would do. People hand off cameras frequently to strangers to have their pictures taken.

A man comes home from work, late at night. A few minutes later, he closes a door and the light goes out. Nevertheless, he sits down, opens up a newspaper, and begins reading. What is going on? (I can tell you now, the man is not blind and the newspaper is not written in Braille.)

Is he in the kitchen? Is it the light in the refrigerator that went out and not the other lights in the room?

Ah geez, you got it right away!! This next one will test you all.

A man with two hobbies took great care to send a letter to an address which he knew did not exist. Why?

Was he writing to Santa?

Cute thought, but no.

A cell phone

This one kind of reminds me of a scene from an old movie. Stay with me and see if anyone can build on this.

The man is a stamp collector and has the only two copies of a rare stamp. He mails a letter to a non-existent address using one of the stamps so that he'll get it back when the letter is returned as undeliverable, but the stamp will have been cancelled. So he'll have made the remaining clean stamp much more valuable as it is now the only one that exists and he still possesses the less valuable second copy as well.

I have no idea what the other hobby could be. And of course, I could be completely wrong.