Yeah, I did that a few times before I figured it out. Yes, there is a way to delete extra pages. I'm just booting my Iliad now, because I can't remember the exact method...
...
Okay, get onto the page you want to delete. Click on the trashcan icon in the bottom right of the screen so it goes dark. Swipe the page with your stylus (you won't see a response on screen to this). Click on the trashcan again so that it goes back to it's normal lighter look. The page should then delete.
(Hey, I don't know if you need to "swipe" the page with the stylus, or just touch the page with it, but swiping feels so tactile and "right"

).
There's probably something in the manual about this, but I don't read manuals until pushing all the seemingly-logical buttons doesn't work (or it blows up

).
Cheers,
Marc