(ignoring any issues with the data)
This is unexpected?!
University courses are different, to suit the different needs of individual students. Of course amounts of work put into individual courses will vary from institution to instituion and subject to subject.
There isn't a national curriculum at university level. It wouldn't be appropriate for that very reason. Students generally live away from home during university, so there isn't the same issues with regional variations as with schools. You just have to pick the best course to suit your ability level and interests.
I certainly hope the government don't decide this is an "issue" they need to resolve as that would probably lead to a form of national curriculum at University level which would be bad.
Leave the Universities to sort themselves out in this respect. Higher education forms a market, unless universities can keep the courses suitable to the demands of their potential students this demand will be lost.