I assume it's like a company secretary. He's not typing up Garry's letters - more making sure that we comply with relevant legal and statutory rules.
It's often quite a high ranking position within private companies, and, with the changes in football over the last 45 years is likely to be a much more difficult job. I suspect that the legal issues around transfers, accounts, stadium management etc are so complex these days that a large part of the role involves knowing when to seek legal and financial advice, and managing those relationships.
Then again...he might just be making the tea.