Depends on the model and version of android. Some of the earlier versions wouldn't let you without the wipe.
On my HTC EVO VIEW 7inch tablet (android version 3.2.1) I can go to Settings, then Accounts & Sync, and touch the Google account in question. Then at the top of the screen there is a trashcan icon that says 'Remove account'. I touch that and confirm by selecting the option 'Remove account'. This removes the account.
However on my Samsung Galaxy 7inch tablet (android version 2.3.5) it requires me to do a factory reset to remove the Google account.
I am no expert so I don't know if this is correct, but I believe the earlier Android kernel versions were set up to keep the first Google account you entered no matter what, and not be able to remove unless you do a factory reset.
You can always add another Google account to the tablet, turn off all the syncing options from the old one (and turn on all of them on the new). And when you go into the market, you can touch the menu key, touch accounts, and then select the new account for the default instead of the old.
But the short answer to your question, if you are on a earlier version of android (pre Honeycomb?) I don't think there is a way to remove the first Google account you created.