I think you only need 3 tables:
Competitors (WCA ID,Name,Surname etc)
Competitions (Comp ID,Name,Venue,Date etc)
Results (WCA ID,Comp ID, Event, Round, Time) (ie '2008CABA03','Essen09','444','1','50.27')
Is that correct? or have I missed something?
Any further ideas?
This would end up in a lot of repeated data for events and rounds and such; the events and round type tables cut much of this out.
You only NEED 1 table for the whole thing, but that's even more spreadsheet-like and less database-like than doing it with 2, etc for 3, but with 5 it's taking advantage of how relational databases work to store less repeated data and make selecting specific bits of that data easier.