I'm surprised this list has survived and grown, but it seems to meet some need.  Given that it appears to be here to stay, yes, some change towards sortable table would help.  Layout-wise, if it was just a list of NRHPs, some of which are further designated NHLs, then a 3 or 4 column table would work to display the information.  There'd be columns for University, State, and NRHP name, perhaps with a "type" column or with color coding for NHLs vs. regular NRHPs.  All 3 or 4 columns could be sortable.  However, some of the university historic districts listed here include sublists of contributing properties.  Not sure how those would work in a sortable table.  Mere contributing properties should not be made to appear to be equivalent in appearance to a NRHP.  Perhaps it could be done as a sortable list with one row per NRHP / NHL, and those sublists could just be included as blocks appearing in a description column?