The Android File Transfer Tool for Mac doesn't support the Tab 10.1 (which is a bit ridiculous, given the fact that Google gave out special Google-branded Tabs to some developers...) because the Samsung apparently uses an unsupported version of the MTP protocol.
At this point, there is no direct way to transfer non-media files, such as documents, to the Tab on Mac OS. You can get the docs on there using Dropbox.
To sync the media files, there are two options: Kies Beta (I have that installed on Lion and it works, but it's a beta and very unstable) or Doubletwist (only over WiFi, not USB). iSyncr, which was my favorite Sync-Tool, also doesn't work with the Tab.
I just got my Tab yesterday and have to say that I'm massively p****d-off about this :-(