Access this window from the menu via
Plugin > LiveTraffic > Status / Information... or via a keyboard shortcut / joystick button you bind to this menu command.
This window offers 4 tabs with the following functonality:
Aircraft List - lists all aircraft known to LiveTraffic with a lot of detailed information and some actions that can be triggered directly from this list
Status / About - general information on number of aircraft, TCAS status, channel status; along with background information / copyright / credits of the software
See the above link for details per tab.