You just need an HTML file with a table in it (which can be named with an .xls extension) and Excel (or LibreOffice) will automatically convert it into rows and columns.
You’ll find this in Applications > Utilities.
It’s a quick/convenient way to get colors from webpages/PDFs etc. (albeit in RGB format) without needing a browser plugin.
What’s encouraging is this may mean Apple are allocating greater resources to Safari development.