I think the questioner is trying to determine what you want to do with the items being paired. Syncing via Bluetooth? Not (yet) possible.
I haven't been looking hard, but I haven't seen too many uses for iPad Bluetooth talking to a Mac. However, you can use a Bluetooth keyboard with your iPad.
What is it you're trying to do between iMac and iPad? More information about your wants and needs will allow us to help you better.