I would suggest you do something unrelated to Accounting as your extra-curricular as it shows you have other interests aside from school, though what you mentioned may be good to show how you've furthered your interest in Accounting related areas, but I wouldn't put it down as an extra-curricular. As Holmstock said, pick something you enjoy and write about that in your personal statement as it makes you more interesting. In my A&F personal statement, I talked about my hobbies of running and singing, which was clearly adequate as I was given an offer, so don't feel like you need to do something too academic. Sports would be a good route to go down if it's something you're interested in. Good luck!