Is there a name for this kind of speaking?

[Bryan_Ekers]

@SpoilerVirgin

Many years ago I decided that if I ever write my autobiography, I will title it “But I Digress…”

Ellen Degeneris had a similar thought for her book: My Point, and I Do Have One…

[Alive_At_Both_Ends]

@pravnik

“Tristram Shandy” is a famous example of the writing style you’re speaking of (although you’re actually writing of a speaking style, but I digress); digressions from the story line, then digressions from the digressions, and then a digression about digressions (or metadigression, I guess), etc.

“Les Miserables” is like this as well. The book is at least twice as long as it needs to be to tell the story.

[Jennshark]

My friend calls it “birdtracking,” because the talker’s words resemble the mixed-up pattern of bird tracks on sandy surfaces.

A woman at work, the most digressive talker I’ve ever met, calls it “branching.” I tried to get the whole story, but then she tangented off onto her niece’s husband’s neighbor-from-1976’s recipe for lemon cake . . .

[PBear42]

Ding, ding, ding. We have a winner. IMHO, “branching” is perfect.