For most top universities, particularly Oxford and Cambridge, supercurriculars (activities done outside of lesson time which relate to the subject you want to study) are much more important than extracurriculars (activities done outside of lesson time which are unrelated to the subject you want to study). While extracurriculars can show you have capacity to do things outside your studies and take on positions of responsibility, unis are generally keener to know why you want to study the course you've applied for and what you've done to explore your subject. If you do talk about extracurriculars which are less relevant to the course you're applying for, make sure to talk about what you got out of doing them, rather than just list the things you do without thinking too much about them. Hope this helps!