I'm not a writer who titles her chapters - though I've considered it for various projects, including my WiP. J.K. Rowling titled all chapters in the Harry Potter series, Neil Gaiman titled his chapters in The Graveyard Book, and there's a whole host of other authors who title their chapters. It's something I think we grow up with because, well, most books that title chapters are children's books. (Ever notice that?)
In Oryx and Crake (heads up!: totally not a kid's book!) the chapters have titles and I think it works because 1.) the titles don't give much away, and 2.)actually serve to intrigue the reader who has nothing else to go on.
Atwood's titles do not give away anything.
In Harry Potter and the Half-Blood Prince, for example, Rowling actually titles a chapter "The Half-Blood Prince." It's like a glaring neon sign to tell readers Skip to here if you don't want the mystery! I know, it's not like she says who the Half-Blood Prince is, but still.
Atwood's chapter titles tend to be one word, and a regular word at that - so it tells you absolutely nothing.
Examples include: "Mango" "Hammer" "Purring"
Titles like these require the writer to explain, through the story, what the hell the significance is.
Admittedly, Oryx and Crake is the first in the series and my previous HP example was the sixth in the series - so there's a certain level of tension going into that new book. Year of the Flood, which I do not have in front of me at present, could have some questionable-give-away-the-story chapter titles.
Atwood's titles are intriguing.
Sprinkled among the seemingly innocuous titles like "Garage" are the more creative bits that Atwood made up and the story is going to have to explain.
Stuff like "Pleebcrawl" "Sveltana" and "Brainfizz." These things mean absolutely nothing, but are interesting words in and of themselves. What do they mean? How are they important?
The juxtaposition of weirdness to normal is intriguing as well. How do you get from "Hike" to "RejoovenEsense"? The promise of the titles leads the reader - even with no other information from the story itself.
To me the table of contents reads like a writing exercise in and of itself. You know - the one the writing teacher always throws at you: "Write a story containing the words perfume, honor roll, and sandwich."
Only Atwood's words seem like way more fun to play with.