I’ve no idea how large Dragon Age: Inquisition is on PC, but since it’s a modern day RPG I’d imagine it’s quite hefty. Hefty enough for a pre-load to be a good idea, especially if your internet connection isn’t amazing.
From today, it’s possible for those who pre-ordered the game on PC to start pre-loading it on Origin. At least, that’s what EA says, and I’d hope they know what they’re talking about when it comes to their own games.
To get started with that, sign in to Origin (you presumably have an account at this point if you pre-ordered Dragon Age: Inquisition,) and click on your Games tab. Then select Inquisition, find the install/download button and you should be on your way.
The game is due to launch on 18 November in the US and 21 November in Europe, so that’s when it’ll actually unlock and become playable. Still, at least you might have it downloaded in advance.