Top and Bottom padding

I have been making changes to the website and now need to alter the row settings and change the bottom and top padding to 10px instead of the 40px default. I was wondering if there was a way to change this without having to select every row and if there was also a way to set 10px as the default for future pages? I am not a designer and was wondering if there was a simply way in which to do this. http://www.inhouserecruitment.co.uk