The Track menu is where one can deal with the tracks, busses and control masters.

Add Track, Bus or VCA…
Shows the Add Track, Bus or VCA… window, where one can add one or more tracks, busses or control masters to the session and define its parameters
Duplicate Tracks/Busses…
Shows the Duplicate Tracks and Busses window, allowing to duplicate the selected track(s) and optionnaly, its playlist
Toggle Record Enable
Sets the Record Enable mode On on the selected track(s). These tracks will record audio/midi next time the global record is active and playback is started.
Toggle Solo
Sets the solo On on the selected tracks, so only these tracks will play
Toggle Mute
Mutes the selected tracks, they wont play until unmuted
Insert Time
Shows the Insert Time window, allowing to insert a blank time in the selected tracks' playlist
Remove Time
Same as above, but to remove time
Move Selected Tracks Up
Changes the position of the selected tracks one track up towards the top. In the mixer, the tracks will be moved to the left.
Move Selected Tracks Down
Same as above, towards the bottom
Height
Fit Selection (Vertical)
Will fit the selected track(s) in the window. If too many tracks are selected, they'll be reduced to their minimum height.
Largest
Sets the selected tracks height to a very high value, hence making the tracks wide on screen
Larger
Same as above, but a little less high
Large
Same as above, but again less high
Normal
Sets the height of the track to its default value which is a trade-off between readability and number of tracks displayed
Small
Reduces the size of the tracks to a low value, increasing the number of on screen tracks
Toggle Active
Toggles the active state of a track. An inactive track will be grayed and wont play any sound. That can be seen in the A colomn of the Tracks and Busses List
Remove
Deletes this track and its playlist (no file is harmed in the process, and the regions from the playlist stay in the Editor for later use)