Answer
We cannot tell anything from that information alone.
Work Step by Step
The scale reading in the elevator is similar with the true weight of the stack of books. This information only indicates that neither the books nor the elevator is undergoing any acceleration.
Since both the elevator staying at rest and the elevator moving at a constant speed have no acceleration, we cannot tell whether the elevator is moving or not, or, if it is indeed moving, in which direction it is moving.
