Many things may happen. Breaking legs or hand is minor factor for a baby because it is cured within a month. A fear may grow about a chair though it is not so harmful. Head injury and spinal injury may cause critical effects in long run , even may be deadly.
If it is scalp injury, bleeds too much, it is less risky. But brain injury may result Alzheimer's disease, loss of memory, visual problems etc. which may occur after long years also. Same with spinal injury as all nerves are connected to the brain through spinal cord.
So if a baby falls from a height , it is better to consult Doctor immediately as the baby can not express anything rather than crying.