A lot of families in Mexico, including my own, use the phrase "ven a echar un taco" (come and have a taco), as a synonym for "come and eat". Since a common way of eating is to have a plate of different foods like: beans, rice, vegetables, meats and salsas, with the hot fresh tortillas at the center of the table. Then one builds their own taco with their choice of filling, or rolls one up to bite alongside bites of the other foods on their plate. Composed tacos are mainly found in restaurants and taquerias, but families will also of course make them, especially for larger celebrations since it's easier to feed guests this way.
In my experience, however, families eat more often in the aforementioned style. Sort of the way you would eat naan with Indian food, or injera with Ethiopian food.
If you visit Mexico and make friends with a local family, it's a great sign of your humanity if they say to you "Ven a echar un taco". Don't pass it up.
by cvalen2