You can then choose whichever fields you would like to output.
To see output in the browser, leave the "output file" field blank, otherwise, adding a file name will cause the output to download.
You can see the description page for this track by going to the browser and click on the name of the track.
For example, hg38:
On the track description page, you can see that these data are a bit old, they were last updated 2014-01-10.
Since these data have not been updated since 2014, it's possible that newer elements have been added.
At the time, I believe all Alu elements were included, not a sub-set. To verify, it is probably best to contact the source:
The source of the data is the Repbase Update library of repeats from the Genetic Information Research Institute (GIRI).