Any default or customized version of the Report that you decide to print, will be fairly screen compliant. Meaning what you see is (basically) what you (will) get.
Absorb has been configured to tell your web browser to only print the active LMS data contained in the layout window that you are viewing - at the time you click on the Print Report button. This means that the whole Report won't be selected for a printout when this option is triggered, but just only what's on the screen in front of you.
The reason for this is that some of the Reports in your portal can very often be pretty long and so having this feature gives you a shortcut to print out just what you are looking at, without having the extra work of setting up particular page range to capture the individual entries you're after.
So while there may in fact be other many columns and other records contained in your Report's data set, if they are not on the actual screen when click the Print Report button (based on the Items Per Page count you have chosen), then they won't be a part of your print out.
Now if you do ever need a paper copy of your entire Report, then that's when you can opt for the Generate Report File button instead and have record of your Report in a file that you can print out in full.