Preview - Play the selected file(s). Press again to stop playback.
Reveal - Reveals the selected file(s) in the Finder.
iTunes - Opens the selected file(s) in iTunes.
Editor - Opens the selected file(s) in the audio editor set in Preferences.
Burn - Brings up the burning dialog, to burn the selected file(s) to CD.
Process - Apply an AppleScript or Automator Workflow to the selected file(s).
Trash - Removes the selected file(s) from the Recording Bin list (Remove From Bin) or places them in the Trash (Move To Trash).