Note: Ya implies that the items stated are taken as examples from a larger group of items. In contrast, to (#6, I-1) implies that the items stated are the only ones under consideration. Ya is often combined with nado (“and such”), reinforcing its basic meaning.
Tēburu no ue ni, osushi ya yakitori ya tenpura nado ga arimasu.
On the table, there are such things as sushi, yakitori, and tempura.
Watashi no heya ni wa, konpyūtā ya sutereo ga oite arimasu.
In my room there is a computer, a stereo, and such.
*2. In the idiomatic expression ya ina ya (following a verb root): as soon as, no sooner had.”
Eki ni tsuku ya ina ya, densha ga dete shimatta.
No sooner had I arrived at the station than the train left.
Ofuro ni hairu ya ina ya, denwa ga natta.
No sooner had I gotten into the bath than the phone rang.