From a good feature on Don DeLillo’s White Noise at PopMatters.
One of the funniest scenes occurs in the beginning of the book when Jack and Babette are in the grocery store (a location a lot of the book takes place in). Out of the blue, DeLillo alerts us to a woman who falls into a rack of paperbacks at the front of the store. It’s just something that happens in the background while Jack and Babette are shopping, but the weird depiction is dropped into the narrative so suddenly, you can’t help but bust up. You soon learn this is a trick of his. When you least expect it, DeLillo drops the sudden odd and humorous image into the storyline.
He also uses this out-of-the-blue trick to underline the gravity of the book’s theme. The first time I noticed this is when Jack is describing Baba, how she "shovels snow…caulks the tub and sink…reads erotic classics aloud in bed at night…talks to dogs and cats" and then, in a new line and paragraph all by itself, he wonders, "Who will die first?"
I haven’t read White Noise, but I definitely caught a sense of this in Underworld. There are pages and pages of dialog in Underworld that simply feel disconnected. One character will speak for several sentences, and then when the next one replies, the reply will be strangely skewed. It’s as though you can see some sort of connection between the things the people are ostensibly saying to each other, but it’s not the sort of normal direct connection you would expect in a conversation. It’s almost as though there are two things proceeding in serial, like two waves that keep intersecting in points.
In a sense, this is the organizing logic (if I can label something so fundamentally disconnected as "organizing") behind the entire book. The book consists of compelling vignettes that are told in fragments, and DeLillo switches among them you don’t really get much of a clue as to why they’re ordered as they are and how they’re linked. Certainly ideas, themes, and characters do begin to assert themselves in your mind as you read the book, but there’s very little by way of authorial direction to explain why things coincide as they do.