I don't know how to do them all at once or if possible but there's a fast way to do it.
You can append all animations to the file first. Or as in your example they were already there.
In the dope sheet editor, Select 1 action to add it to the NLA Editor.
From NLA Editor,
With mouse in the
strip window, hit N to open properties panel so you can see the end frame of each action you add.
Push the action down into the stack.
If you want all actions on one strip, Select the strip in the
strip window and note the end frame number.
Advance the timeline to that number +4.
With mouse in
strip window, Shift + A.
In the popup search dialog you can backspace any action already selected to get a list of all your actions.
Select desired action and it will be added to the strip where the timeline is set at.
Repeat for each action.
Note that this process will create a new Action from any action that is already in the strip, just the same as if you were in the Action Editor and hit the + button with that action selected.
To create separate tracks, everything is the same except you Shift + A in the
track window to add a track first before Shift + A selecting the action in the