Ok, well not sure why 3 spaces seems to have ballooned to 5 in the first few rows.
But anyway, here's what it looks like, as soon as I click "Edit" (but before clicking or typing anything else):

although that section is rendered in a monospace font, note that all the whitespace has collapsed down to a single space.
(I didn't click "Save" so the whitespace in the previous post is preserved)
Not the most important bug in the world, but it's a hassle if you go back and edit a previous post because of typos or to correct/add info etc. and now you have to line everything up again in the table. I have not verified, but would suspect, that this bug affects wikis as well since it is the same editor?