So does mine, but for a gramme counter the airline ones are less than half that size.
They're given out on overnight flights, for single use, but if used sparingly they're enough for 3 or 4 morning brushings on a multiple-day hike.
Edit: Just checked with the OH, she says when you board there is a folded blanket on your seat with a plastic bag or a pouch on top of it, and this contains the aforesaid toothpaste, a two-piece travel toothbrush, eyeshades, earplugs and flight socks. So, there are some useful things there!