3 Reasons Not to Fix a Mousepad Bubble
The bubble is delamination The rubber base has separated from the cloth top. Heat or pressure strong enough to re-bond them will likely melt the rubber or warp the surface texture.
You’ll make it worse Attempting a repair usually leaves a lumpy, uneven mess that’s worse than the original bubble. The success rate is low.
Replacement is cheaper and easier Cheap mousepads cost $10–20. Just replace it. Even for expensive ones, replacement is the better option.