Other times it's a way to placate a grumpy restaurant patron, as NYM's Grub Street blog reports:

Our waitress forgot the main course which was a salmon puttanesca (one of the specials of the day). I could hear the owner (35ish, Latin) admonish her. He then came over to our table with three cigar tubes saying "Here, please take these; they're Cubans. Just don't tell anyone or else I'll get in trouble." The tubes say Romeo Y Julieta—Havana, Cuba.
Grub Street writes that this incident occurred at "a certain Italian restaurant on Ninth Avenue in Hell's Kitchen." We put on our detective monocle and decided to give this one a go. Our semi-educated guesses after the jump.

We sleuthed around the NYM website and came up with the following Italian-on-Ninth-Ave.-in-Hell's-Kitchen suspects, though quite frankly, we're at a loss as to which it could be: