Hi Shi_Charana!
I perfectly understand. However, there is no real way to make it faster than it is. The map has to load, so if it takes 10 minutes on your PC, it is because it requires 10 minutes.
What you can do is separate your level in sublevels and hide those you don’t need to see while working. Opening the level will then be faster since the engine won’t have to load everything, just the visible sublevels.
You can also try to optimize your level, whether by reducing the polycount, optimizing the visual effects, cleaning up your blueprints, etc…
I hope these guidelines would help :).