What are the practical uses of "FOR...NEXT Loop" in Qlikview

[#1]

I have gone through a bunch of reference materials about loops but have not been able to understand how they actually work and most importantly why are they used in real time scenarios. Can someone attach a file with sample data where this is done and explain why it was used. Most commonly the "For ..Next Loop" as this is what I have seen being used in my company with counters and peek function.

[#2]

There could be numerous scenarios but I have attached a file with one particular case where you want to load say multiple tables from the database and store them all into their respective qvds in one go then you could use it.