Sharpoint list - Showing HTML text

It's because of the column type you're using - probably rich text. The easiest route for text fields is to just use plain text type in the SharePoint list instead, but iirc if you convert the existing column it'll have whatever HTML was in there when it converted so it's kind of a pain to switch midway through. 

As far as keeping it, there's not a great way to display the HTML text in the core table visual to my knowledge - there are HTML visuals in the app store, but using it in the core visual table is not really a thing outside of SVG.