The problem that I see with that is it makes editing a table very difficult. Sure, if you know exactly what you're going to put in a table, then it might be worth it to draw all of those lines, but as soon as you need to go and edit the content of a cell, or remove a column or something, you might have to go and edit unrelated parts to maintain your formatting. It also seems like it'd be a real pain to parse. I'm not sure I know of a better solution, except to suggest that markdown might not really be suited for tables, and it's better to just use HTML for that part.