What has greater gravitational potential energy - a book lifted 1 meter off the ground or the same book lifted 10 meters off the ground? Why?

The book lifted 10 metres. This is because it has been raised to a higher potential in a field because the field has a greater ability to do more work on it due to the larger distance. This can be seen in the equation G. P. E = m*g*h where gravitational potential energy is directly proportional to the height.