Tabulate means:
to arrange information in an organized way so that it can be studied,
recorded, etc.
"Tabulated" is (in the sense we're interested in here) treated as an adjective, meaning having been arranged as above.
"Untabulated" is simply "tabulated" with the "un-" prefix added. "Un-" simply means "not", so "untabulated" means "not tabulated". "Un-" may be used with pretty much any adjective, so the fact that "untabulated" isn't found in a dictionary is not a matter of concern.
"Unreported" might also be used, but one wonders if you don't mean simply "not shown here", which is not precisely what either word means.
It seems to me that you should perhaps use plain words to describe the situation, vs trying to find the "perfect" hair-splitting word. Eg, "As a test of the robustness of the results I have performed an analysis of a similar yet different set of data (and received essentially the same results), but I have not included those details in this report."