Why do cats knock things off tables?
The Real Answer
Usually because pawing at objects is normal investigation and play, not because your cat has developed a personal objection to your belongings. Cats naturally stalk, swat, pounce on, and manipulate things, and an object near the edge of a table gives immediate feedback when one paw makes it move—or sends it to the floor.
Cats can also learn from what happens afterward. If knocking something down reliably makes you look over, get up, speak to them, or otherwise react, your response can make the behavior worth repeating. So the motive can vary between curiosity, play, boredom, and learned attention-seeking; there isn't evidence that cats are knocking things down because they understand the financial or emotional value of the object.
A cat will push something off a table while maintaining direct eye contact with you, waiting to see if you understand that you have failed as a caregiver. Maybe it’s testing the object. Maybe it’s testing your reaction. Either way, your coffee mug just became the practical portion of your performance review.
The Dunce Dynamics Institute Examines Why People Ask This
The behavior looks deliberate enough that people start assigning motives to the cat, especially when the object was valuable. The safer explanation is that ordinary investigation, play, boredom, and learned human reactions can all make the behavior worth repeating.