Final answer:
The reaction force exerted by a table when you push down on it with your hand is directed upward, in accordance with Newton's third law which states that every action has an equal and opposite reaction.
Step-by-step explanation:
If you push down on a table with your hand, the corresponding reaction force will be directed upward. According to Newton's third law of motion, every action has an equal and opposite reaction. Hence, when you exert a force on a table by pushing down on it, the table exerts an equal force in the opposite direction. This is why you can feel the table pushing back against your hand.
In the context of gravity, when you push down on a table, part of your weight is transferred to the table. As a reaction, the table provides a supporting force that acts in the opposite direction to your weight, which is upwards. This reaction force is what balances the downward push of your hand, keeping the table stationary (assuming it is not overcome by the downward force).