Turn HTML into clean, portable Markdown - here in this tab, with nothing uploaded.
HTML pasted for conversion is often a page from an intranet or an email - not something to hand to a third party. It is converted in this tab and goes nowhere.
They are dropped. Only the content and its structure make it into the Markdown.
Yes, to GitHub-flavoured Markdown tables. Tables too complex for Markdown - merged cells, say - are kept as HTML, which Markdown allows.
For copied rich text, the Rich text to Markdown tool reads the formatting from the clipboard, which is easier than finding the HTML source.