Uhh ... gotta say it, but ...

The most-significant textual clip from the OP, IMHO, is this one:   The most important line is header("Content-Disposition: attachment; filename=BOBreport.xls"); I need to have it in my perl script to export a html table data to Excel.

It quite-frankly appears to me that the OP is most-interested in the output of the aforesaid (PHP ...) code.   If this is indeed the case, then there is in fact no actual requirement to “translate the following PHP code to” ... (anything!)

If you are only concerned with the (HTML) output of a computer program, then you do not care in the slightest what programming-language was originally used to generate that output.

If the Perl program that you contemplate is destined to be a client of the program that (somehow ...) produces the “HTML table data,” this Perl program need only be concerned with “how to correctly parse this HTML data, regardless of its source.”

On the other hand, if the Perl program that you contemplate is destined to replace entirely the aforesaid program as “the root-source of the data being sought” ... then both PHP and the HTML that it now produces become irrelevant.