Rendered html table seems not to respect layout

Hi, I’m very new to hugo and not quite sure if it is an hugo issue or not, so sorry if it isn’t.

I’m trying to contribute to notepad++ manual by adding missing API definitions.
The description of this API is using html tables and here it starts getting weird.
The table layout uses percentage for the cell width and if I put everything in a html page then the browser renders it like I would expect but if I use hugo then the cells width seem not to respect the settings. Means the size used is different.
For example see here

Obviously there is something I’m missing but searching the web and this forum wasn’t of any help. Any ideas?