Entities taking too much sources from internet connection

So i've been playing on my friend's realm and i realised that the cow farm we had (like 50-70 cows) was drawing too much upload speed from my internet connection, i dont think its only cows that can cause this issue but all entities (in large quantities) on the game. The tricky part is  the owner of the realm (my friend) doesnt get any lag at all, and he have the same upload speed as mine. So my conqlusion is if a player is not the owner of the realm, entities can cause him to lag by continiously informing the realm server that he loads the entities? But owner of the realm sends like half the data i send? I know it may make no sense but we've tested that.