Hi,
Yes unreal like many softwares will use the resources available on your PC at launch to precalculate a lot of things, which is normal and not a problem; computers are made to use their ressources. Its only become a problem if the ressources stay stuck at 100% for a moment ( several minutes).
Also the load is only at the beginning, unreal release the ressources after a few seconds. The game have been tested on differents computers and I didn't see any problems, game runs smoothly on every rig I tried. If there is some issues during the game it might be issues on your side...
Anyway I'am glad you like it :)

