The U.S. government is releasing the Census redistricting data in this format on FTP and I don't know how to open it. I think they are supposed to be Tiger Line Shape Files, but they directory structure does not match what I would expect from the the Tiger Line Shape Files documentation.
They are .pl files, but I know they aren't really Perl files!
I'd like to get them into a Excel file, with headers on the top like "total population," "Caucasian population," etc.
The PL files are text files which contain the data you are looking for. You probably won't be able to open them in Excel
Alabama alone contains 319,739 records.
The easiest way to use these files is to load them into a Database and run queries to extract the data you need. Access templates are provided in the FTP you linked to.
There are no ESRI Shapefiles in the FTP you linked to, the shapefiles provide the geometric descriptions of census boundaries, Counties, Tracts, Congressional Districts, etc.