My understanding of iTunes Match is that all your music is "matched" and stored on Apple's iCloud. Then, you can play music on the iPad via streaming. So, you can pay for iTunes Match and then, once everything is matched, you can then delete all the music you physically have on the iPad. You'll just be streaming it.
However, one thing to be aware of is that the music in the cloud will be downloaded to your iPad while it's streaming. So, you will have to go into the Music app and delete that music every now and then so that your iPad doesn't fill up [again].
So, in a way, you'll still have to manage your music because you will have to keep removing it from the iPad. But, this way, you can have access to all your music versus just the music you can fit on the iPad.
Hope that clarifies.
Marilyn