If your cat likes to leap onto the counter or table or anywhere else he should not, make the area as unattractive and unappealing as possible. Pet manufacturers make nontoxic repellents that you can spray in most places.
Cats do not like the bitter scent and will avoid it. You also can cover the area with plastic wrap, aluminum foil, or double sided sticky tape. Or you can always clap your hands loudly, and say "No!"
Then pick your cat up and place him on the floor or in his cat condo. Keep doing this until he understands. It is always a good idea to show him the correct place to sit or jump, such as his cat condo, a chair near a window, or another acceptable area. This is your way of telling him "You do not belong on the counter, but you can sit on this chair."
Do your part to help your cat do the right thing. If he goes onto the counter or table in search of a snack, do not leave food out to tempt him and then punish him for doing what is natural hunting. Some cats like to investigate the sink and will lick leftover food off dirty dishes or pots.
If your cat does this, cover the dishes with soapy water. He will quickly decide that it is something he does not want to taste. Another solution is to remove the temptation and put the dishes in the dishwasher or wash them right away.
As with children, cats need to learn what eh boundaries are in the home. With a little reinforcement and training, you can cure your cat of jumping where he should not.
An over stimulated cat could frighten or scratch a child. Always instruct children to ask permission from a cat's owner before trying to pet or play with an unfamiliar feline.