Most players who watch top players play look like this. That link should take you to a 22-second video of five cats looking side to side as they watch a ping-pong match. Those cats are enjoying the epic match they are watching, but they are not learning anything. All they are seeing is a little ball go back and forth.
Instead, zero in on and watch one of the players and what he does. Focus on specific things - the feet, positioning, serve, receive, strokes, placement, shot selection, etc. Ideally, watch a game several times, each time focusing on something different. That way you can really learn what the top player was doing, and learn from it. If possible, watch parts in slow motion. For the tactical aspects, think about why the player did what he did, and how that might relate to your game. For the technique aspects, get up and shadow-practice what you saw. If the player you are watching can do it, so can you!!! (At least you can strive to, and you'll get a lot better that way then if you don't. It's a lot easier learning new things by shadow-practicing first without the ball, and then later working on it at the table with the ball.)
If you just watch the match as a spectator, all you really see is a ball going back and forth, back and forth, back and forth . . . nice kitty!!!