I told myself that I should be polite about this, but let's face it - wiki tables are ugly. Fortunately, the wiki already attaches a class, wikitable, to the table tag, making reformatting fairly easy (though the wiki also attaches a 'border' attribute to the table tag, making some formatting difficult if not impossible).
I have modified the code so that the generated table tag does not use the 'border' attribute, and also defined styles in wikiStyle.css to make tables look nicer. The color scheme fits in nicely with the Renaissance theme. Let me know if you are interested in the patch and I will open a JIRA and attach the patch.
By the way, I resisted the urge to convert all the tags into lower case (e.g., TABLE -> table), which was very hard, especially considering that the portal generates pages using xhtml... I assume there is already a task to make the wiki output xhtml compliant?