I don’t think there’s a loose narrative structure in it. The lyrics and lyrics meaning page at Green Plastic, which is usually very reliable, mentions that “Motion Picture Soundtrack” from Kid A was originally supposed to be on OK Computer. Thing was, Thom Yorke liked it and the rest of the band didn’t, so they left it off (and he got it on Kid A). This kind of messes up the idea that the whole album has a narrative structure.
However, there might be a theme to a few of the songs. Thom has said what certain songs are about, though, and a lot of them boil down to certain experiences/dreams he’s had (“How to Disappear Completely” is about a dream of floating).
OK Computer is a similar thing (and the meanings of the songs have been made pretty clear by the band). For instance, “Karma Police” came from a joke of the bands when they were on tour. If someone was in a bad mood they were told to watch out, or the Karma Police would get them. “Exit Music (for a film)” was originally written for the film “Romeo & Juliet”, but Thom thought about the older version when he wrote the lyrics. “Subterranean Homesick Alien” pays homage to a Bob Dylan song and is about a couple of experiences in Thom’s life.
The meanings of each song are so varied that I don’t think there’s a running narrative in them. But again, there could be themes you could find.