The simplest technique is to fetch the page by URL with LWP::Simple, and extract the table with HTML::TableExtract. If the site requires more elaborate navigation in order to produce the table, you might need WWW::Mechanize. But Mechanize may be overkill if all you need is to fetch a document at a specific URL.

Once you've fetched the document and parsed out the table, I assume you know how to plug it in to Excel, as you mentioned you already know how to insert text into an Excel document.

Rather than provide an example of using LWP::Simple and HTML::TableExtract myself, I'll refer you to the synopsis section of their documentation. Both of them have good documentation and easy to follow SYNOPSIS sections in their POD. You can do a lot better by reading the POD than by looking at my cobbled-together example.