Newbie - Trying to add column to a table

I've inherited a website which has a 4 column table (http://www.wakeresearch.com/current-studies). While I can make content changes, I'm not very well versed on changing the structure of a Drupal site. I'd like to add a 5th column in this table. I have no idea where to begin. The admin dashboard includes Content, Structure, Appearance, People, Modules, Configuration and Reports. I've poked around but can't seem to find where to edit this. Any help would be greatly appreciated.