Best way to edit purchasetable css in membership plugin to create padding

I need a few pointers on how to edit the purchasetable css to increase the space between the text and the price – you can see in the screenshot that in some cases the text and the price bump up against one another, making it difficult for a user to understand the price of the membership they are about to buy…

(and self-conscious note (!) – one of the title's of the plays listed in the text is a little racy – it's actually a very serious show being performed by a fullbright scholar!)