You will expect this size when you are updating your Windows 10. Mine is more than 3GB for sure. Imagine if you only have 1 mega bit line in South East Asia countries then how long will you take.
Only 2 weeks I have not power on my laptop and this is the size of update that I will get. I spent 4 hours to complete the download without installing.
I continue to leave the update untouched, the laptop completed the update using more or less 5.5 hours. By the way, I am using AMD A6 with 8 GB RAM.
I think Microsoft need to see how to improve this. Not everyone is living in USA, and not every country having the same Internet infrastructure.