This is a package version of nfssfont.tex (part of the LaTeX
distribution); it enables you to print a table of the
characters of a font and/or some text (for demonstration or
testing purposes), from within a document. (Packages such as
testfont and nfssfont.tex provide these facilities, but they
run as interactive programs: the user is expected to type
details of what is needed.) Note that the package mftinc also
has a \fonttable function; the documentation explains how avoid
a clash with that package.