Opening it in IE, Vivaldi (Chromium based) or Safari (iPad) the columns are off a little bit - although the spacing is off by the same amount in all three of those. Of course, I might just have something in FireFox set that is making things slightly different (if I zoom in a little - the FireFox spacing matches the others).
Right now, the only way to know things will look as intended here in all browsers is to post an image of the table - it even works for phone browsers because they can just zoom in if needed. Unfortunately, no copying and pasting of any data is possible - although you could put a link to the data (from Dropbox, Google Drive, etc.) if people requested it.
I usually use Lucida Console for a fixed width font because I like the look of a sans-serif font rather than something that looks like an old fashioned typewriter.
To do a chart for a forum, I typically create it in Excel (or similar spreadsheet program) because making changes is so much easier and there are the normal features like summing cells, averaging, inserting charts, importing data, etc. You can just set the fill color for the cells to white to make the cell borders disappear for screen captures.
For an image host, I normally use Imgur because it's quick and easy - I never worried about the possibility of deleted non-viewed images because most of my forum posting is transitory in nature. I don't much care if it gets deleted sometime next year - although I don't recall ever noticing an image that I uploaded to their servers getting deleted (probably because I rarely go back to check).
One more tip - if you want to prevent a web address from becoming a link, picture, or video here, you can insert some useless html tags to prevent the DU software from recognizing it as a URL. For example:
htt[b][/b]ps://imgur.c[b][/b]om/QMhFGR1.p[b][/b]ng
...becomes...
https://imgur.com/QMhFGR1.png
(I tend to put in more empty tags than needed because iOS sometimes tries to make even partial addresses clickable.)
The benefit is that the text URL can be copied and pasted because browsers only care about the content text, not the html tags.
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