Thanks for the report, and for the manpage.
/usr/bin/showtable actually conflicts with libdata-showtable-perl. I am
not really happy to use the ".py" suffix for the rename, since usually
utilities should not have language specific suffixes. Instead. I opened
an upstream issue
Let's see where this goes.
showtable.1 in casacore-utils however referred to a binary that was
renamed to "showtableinfo" at some time; I just forgot to remove the
manpage. This will be fixed with the next upload of casacore.