No. According to Newton's first law, an object at rest or in motion will remain at rest or in motion with constant velocity unless acted upon by a net external force. Therefore, if there is only a single force acting on the block, it will either start moving or continue moving at a constant velocity if it was already in motion.
No, it is not possible for the block at rest to have only a single force acting on it. For an object to be in equilibrium, the net force acting on it must be zero. In this case, there must be at least two forces acting on the block, one being the gravitational force (weight) pulling the block downwards and the other being the normal force exerted by the table that counterbalances the gravitational force in the upward direction. These two forces must be equal in magnitude and opposite in direction for the block to remain at rest.
