css of Tables in README files looks too narrow

Any tables in .md files are rendered with minimum width. Because of this, text with white space is always wrapped and just looks ugly. I found no way to edit the css directly, only with custom css injection using addons.

Is there any reason the css of tables looks that way?

Markdown

header | this is a really long header, because we want to use really long text
 ----- | --------------------------------
check  | This is a custom description and requires lots of text

rendered