Mayo in cornflakes was literally the only really weird combo I saw, through a quick browse. Most were just variations of the sweet/salty thing.
Rice with ketchup weird? I guess most people here haven't been actually short on money in their lives. Macaroni and ketchup is more or less a staple in student food here and it was a very small change to go with rice or ramen instead. When money is good, it's macaroni/rice with canned tuna :P