Instead of a list of "majors," you'd find a list of subjects offered at Oxford, which includes:
* Humanities: Classics, English Language and Literature, History, Philosophy, Politics and Economics (PPE), Modern Languages, Theology, Music, etc.
* Social Sciences: Anthropology, Economics and Management, Sociology, Politics, Geography, Psychology, etc.
* Sciences: Physics, Chemistry, Biology, Mathematics, Computer Science, Engineering Science, Materials Science, etc.
* Other: Medicine, Law, Archaeology, etc.
The specific subjects offered and their sub-specializations are extensive and best explored on the University of Oxford's official website. You'll find detailed information on individual subjects and what courses are included within each. Searching the website for "Undergraduate Courses" or "Undergraduate Subjects" will be a good starting point.