Hi Darren,
Quick question...did you create a Smart Campaign or Smart List? The latter might be the case in that you're trying to add a column.
Most columns are fields within Marketo that are associated to a contact, so you wouldn't necessarily have a behaviour in there like the date someone clicked on a link from the landing page. You could in theory create this as a field and create a smart campaign that time stamps it, but might be a bit tedious to do this for every one of your campaigns.
Could you give a bit more insight into what you're hoping to get out of the report? Maybe there's another way to get your information.