multiple -e command scan be combined on a single line
sed -e 's/#.*$//' -e '/^\s*$/d' /etc/webalizer.conf
-e 's/#.*$//' <- this looks for the # character followed by any single character (.) and then (*) repeats the previous 'any single character' zero or more times, catching comments with no characters afterwards as well
-e '/^\s*$/d' <- this looks for lines that have no characters from the start of the line (^) to the end of the line ($) and deletes (d) them.
-e '/^\#/d' <- this would have also removed any lines with comments on them, with the # at the start (^) of the line