What HTML is
An HTML table is a table element containing thead and tbody, with th cells for headers and td cells for data.
Web pages, email templates and anything pasted into a CMS.
What reStructuredText is
reStructuredText simple tables underline the header with equals signs and align columns with spaces.
Python documentation, Sphinx projects and anything on Read the Docs.
What changes when you convert HTML to reStructuredText
The first table in the markup is used. Cell contents are stripped of inline tags and entities are decoded, so <td><b>Total</b> </td> arrives as Total. Nested tables inside a cell are not descended into.
The equals-sign rule under the header is what tells Sphinx the first row is a header. Without it the table renders as data with no heading.
What carries over from HTML to reStructuredText
HTML records 2 things about a table that reStructuredText has no way to hold.
HTML can hold a value that is itself a list or an object. reStructuredText has only flat cells, so nested values are flattened into one cell rather than being spread across columns.
Anything visual in the HTML - weight, alignment, colour, column widths - has no counterpart in reStructuredText and is dropped. The values are what survives.
The identifier 007 comes out of the reStructuredText as 007. Reading it as a number would have made it 7, and an id that changes value is worse than one that stays text.
The role "Analyst, data" survives with its comma, in one cell rather than split across two. That is the first thing to check in any converted table, and the usual place a reStructuredText file goes wrong.
The quotes around Jonah "Jo" Pryce are left as a plain quote character in the reStructuredText.