To line up columns you can use Perl's formats (see the perlform docs for info), or perhaps printf. If you're outputting HTML then you'll probably use an HTML table, which is...an HTML issue, not a Perl issue.

Of course output is printed horizontally by default, and I'll assume that's what you really do mean. The challenge is just to line up columns, which can be done using formats or printf, as previously stated. If you're instead asking how to print vertically the answer is going to be much different.

Actually, the correct way to generate table HTML output is using a template. I prefer HTML::Template, but Template::Toolkit is all the rage.