Odd question.. How do I get my bluetooth headset to handle the audio/mic for my tablet?
Bluetooth Profile Widget may help you. It allows you to set the profile for your headset to, well, in this case, headset, so that the tablet will treat it as such.
Note: Certain headsets do not handle all audio (Music/video players) only phone audio, which would not apply to a tablet (obviously :P). There are settings in this app to force all audio, including music and such, out the headset if it does not work with the default profile.