The stats that most people care about are R which is Impedance, and X which is Reactance. An X of 0 is Resonance. Together R and X make up what is known as Complex Impedance, generally written as R±jX. Explaining their relationship can get complicated from this point.
The Z is actually referred to as "The magnitude of Z" and is properly written as |Z|, although many antenna analyzers just use the letter.. Together with the phase angle (or "PHASE" from above) is another way of getting to the same point as R and X written about above, and is simply another way of writing out the Complex Impedance. Most people in the hobby world don't use these.
RL is return loss. What this represents is the amount of signal that was transmitted that did not make it back to the measuring device, essentially the loss of the signal, and it is always represented as -dB. Many people make the mistake of this "return loss" as being how much of the signal was radiated, which isn't completely false, but they often don't consider that this is also factoring in losses in the antenna system. If your Return Loss goes up, it could be an increase in either of both, and likewise if it goes down it could be a decrease in either or both. Just like lower SWR does not necessarily mean your antenna is performing better, a greater Return Loss does not necessarily your antenna is performing better. It is heavily influenced by SWR, and is considered by many to be another way to show what SWR is showing. This can be useful for things like measuring the losses of a run of coax and such if you know how.
L is inductance, or the measurement of a coil, and is measured in Henrys, which is H for short. In the list you gave, nH would be nanoHenrys, which is 0.0000000001 of a henry.
C is capacitance, essentially the capacitor version of L above and is measured in Farads. Again nF is nanoFarad, and is as nanoHenry above.
At first glance, I don't see anything significantly wrong with what you have posted. Some people would tell you to get X to 0, but you won't notice a difference in performance from where you are now if you do that.
Do you have any questions on any of this?
The DB