What is ODT?
What LibreOffice, OpenOffice and Google Docs save a document as, and the ISO-standard counterpart to .docx. Inside it is a zip of XML, which is the reason a table drawn in one can be read back out at all. It is a page format first - paragraphs, page breaks, headers, footnotes - so the only part of it that is data is a table someone drew on the page.
What is HTML?
The web's document format, and incidentally a place an enormous amount of tabular data ends up - published tables that were never offered as a download. Pulling those out is usually easier than asking whoever published them for the numbers.