I use my iPad all the time for reading and I never have an issue holding it by the edges. If you do have an issue holding the tablet by the edges, a new case called the FreeOneHand might be exactly what you need to get more comfortable use out of your device.
The case is a clip on holder that grabs the iPad by each corner. On the back is a knob that you can grip with one hand to allow you to have your other hand free. The way you hold the iPad when it's in the case is supposed to be more ergonomic. The front side of the holder has raised feet that protect the screen if you lay the iPad face down.
The knob also tilts the screen at an angle towards the user when you lay the iPad on a flat surface. The FreeOneHand case weighs 2.3 ounces and can be had in several colors including Bright White, Silver, Ebony, Lime Green, Sky Blue and Rose Pink. You can order one up for $39.94.