The Track Momentum Window shows the different particle tracks in the detector. In the upper bar you find buttons to get to the previous or the next event. With File→Animated Event you can see the event in motion.
The entry Show simulated is not necessary and should not be checked.
After the name of the event file you see the missing energy ETMis in GeV which is a result of non detectable particles (i.e. neutrinos) or measurement mistakes.
The table shows from left to right the track number, the energy of the particle, its charge, the transverse momentum (the momentum vertical to the direction of the incoming proton beams) and the angle of the track (the original particle beams are in z direction and you see the x-y plane in the Canvas Window, described on the next page).
If you click on a row, you see the associated tracks highlighted in the Canvas window described next page.