i had 4 hours of classes that were generally boring, some of which was useful but it was mainly just revising all the work i had done the week before. everyone just sits there for an hour trying as hard as possible to ignore eachother. then there were 8 hours of lectures, and i found these to be quite enjoyable for the most part. sometimes difficult to follow, and sometimes easy.
my timetable was a bit crap, i had to be at lse 3 times per week at 10am and once at 9am... only on tuesday could i get a lie in until 11...
aside from the standard 8/4 hours lectures/classes there were also some supplementary lectures/classes. i always went to the MA100 help session, and there was also a ST102 help session that u could of gone to.
as for the work outside of classes and lectures... obviously its not the same each week. sometimes there will be big pieces of work etc. i'd say on average for each of the 4 modules i did maybe 2-3 hours of work towards the exercises to be handed in the next week and maybe 1-2 hours of reading, so between 12-20 hours works extra per week. maybe more, i'm not entirely sure. the exercises themselves don't really take that long if you understand well what is going on, and you can just botch them and wait for ur classes to explain them. but i never really did that except in stats, and sometimes i would spend ages trying to understand the maths exercises. plus if u want to do all "compulsory" reading it may take ages. for the AC100 module for instance there is loads of reading, especially for management accounting, though it isn't necessary really. on the other hand EC102 reading is necessary in my opinion and there is a lot of that, as some of the concepts may be quite difficult to understand at first..
but of course you can be like my friend, who really did very little work, but still managed to get a first with a combination of last minute revision, a flukey EC102 mark and a very easy stats paper... but as davemarkey says, unless u work consistently hard it is very easy to fall behind..