Your cat walks up to the edge of a table, makes deliberate eye contact with you, and slowly, thoughtfully pushes your pen off the edge. They watch it fall. They look back at you. This is not an accident and it was not a mistake.
There are a few things happening here, and "spite" isn't one of them — but "deliberate strategy" is.
Attention-seeking, and it works
The most common reason is the most obvious: you react. Every time your cat knocks something over and you say "no!" or pick it up or even just look over, they've gotten exactly what they wanted — your attention. Cats are excellent at learning which behaviors reliably produce a response from humans. If knocking your phone off the nightstand makes you immediately engage with them, that behavior gets stored as useful.
The fix is brutal but it works: no reaction. Don't look, don't respond, don't say anything. Get up and leave the room if you have to. Remove the audience. This takes consistency, and a cat who's spent months being rewarded for this won't change in two days — but the behavior does extinguish when it stops producing results.
Prey-testing instinct
Cats use their paws to test objects before picking them up or biting them — the same way they'd bat at a potential prey animal to see if it moves. Pushing something off a surface and watching it fall is an extension of this. Moving objects are interesting to a predator. A cat that bats at small objects on tables isn't trying to clear the table; they're investigating whether that thing does anything interesting.
Boredom
A cat that's well-exercised, well-stimulated, and has enough enrichment to occupy itself doesn't need to create entertainment by pushing your belongings onto the floor. Cats that table-clear frequently are often under-stimulated. More interactive play before the times they tend to do it (often evenings), a bird feeder outside the window, puzzle feeders — these things redirect the same energy into more acceptable outlets.
If your cat is also very vocal at night, both behaviors often come from the same root cause: a cat with energy and attention needs that aren't being met during the day.
Practical measures
Clear tempting objects off surfaces if you care about them. Cats tend to target the same types of objects — small, moveable things at the edge of surfaces. Putting your water glass in the middle of the table won't satisfy a determined cat, but it removes the easy opportunity. The combination of no reaction plus more play tends to work better than either alone.