Question

If each object in the unoverse attract each other why dont two books kept on a table come towards each other amd collide give reason

Answer 1

Because the force (i.e gravitational force) is relatively weak for huge celestial bodies.

Hence between two books the force is negligible

Answer 2

Everything in this universe which has mass is always getting attracted towards each other due to GRAVITATIONAL FORCE.   Gravitational force F =GMm/r2 The gravitational force is directly proportional to it's mass. Earth , Moon,planets , Sun have large mass and hence their gravity has an effect on us. But books and we humans and everything small has a very small mass and it's gravitational force is so small that it is almost negligible. And hence two books on a table will never on their own move towards each other and collide . I hope this helps you :)