The reason it bugged me so much was that there's always drinks and remote controls on the end table, and sometimes there are lottery tickets. What I really wanted was a custom end table with walls on 2-3 sides to stop Sam from jumping up. Plus maybe a second, higher surface to replace the TV tray where my laptop goes when not in use. But custom furniture is expensive so I wasn't in a big hurry. To tide me over, I made a wall on three sides out of a cardboard box that I stapled on.
But that end table is very old and the top was showing its age, so I knew it was time to do something. The top especially was heavily damaged by water from years of not using a coaster. It's a cycle: it's not nice enough to bother using a coaster, it's getting worse because I don't, etc.
Since there's plenty of time these days for online shopping, I decided it was time to see what I could find that would work as-is or at least be easy to modify. I looked at page after page of end tables and I'm pretty sure it was actually on the last page of results on Wayfair where I found the one I ended up buying.
The little fence it has around the perimeter isn't tall, but it doesn't need to be. I'm pretty sure no cat would ever try to jump up, and Sam hasn't that I know of. I figured before I even ordered it that it'd never be an issue, and even if it was, it'd be far easier to attach something to the metal bars than it ever would directly to wood.
I had to take the wheels off, though. They're swivel wheels, so even with the two that are lockable locked, you can scoot the table back and forth way too easily. I didn't need to move it around on the wheels so I don't miss them.
The old end table has a storage compartment and it was still useful, so that's in my office next to the futon. I still keep my keys in it, and after several months I'm still always walking out of my office dressed for my walk and have to go back in because I'm still not used to keeping my keys in my office. It happens less and less, though.