Two things:
Invest in a queen-size bed. Twin beds are far too small for any adult. Especially one who frequently takes books or tablets to bed with them. (Oh dear, this subject can get risque, can't it?) Suffice to say you want to make sure your tablet ends up falling out of your hands into a nice cushy bed, not the floor. Even a fall to carpet can be disastrous if it happens to hit on the edge. Or worse, you forget and step on it on your way out of bed in the morning.
Orientation lock is my friend. I almost always use my iPad in landscape mode so it tends to stay locked. I prefer web browsing and reading books in landscape mode. Books especially are nice with two side-by-side pages. In fact I prefer reading books in this e-form to their paper alternatives because it is just so easy to turn pages. Prop the reader on a pillow or comforter, tab your finger and the page flips. I can easily read 100 pages doing that.
Reading ebooks in bed at night is one of the ways these LCD tablets shine over the e-ink Kindles. They come with their own booklight. BN's Nook app is especially nice. It has a theme called "nightlight" that switches to white text on black screen. So you don't get excessive glare from the screen. I find I always have to turn brightness way down on iBooks and Kindle apps.
And like I said, you can read or watch whatever you want, fall asleep and your tablet will shut itself off. Then when you wake up you can just flip it on and resume, or check your e-mail and the morning headlines.
I guess if you are a restless sleeper it's not advisable to try this. You wouldn't want to kick the iPad out of bed. Mine tends to stay where I put it at night.
Um, I guess those sharing beds would also want to think twice. Imagine the service calls on those mishaps: "Um sir, exactly how did you crack your screen in so many places?" "Well my wife and I...

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