Editor is lagging

I have one-scene 3d game and there are a lot of objects placed in it.When i want just to turn the camera in the editor for example to the right or to the left it lags and move nearly in 1-2 seconds.After building the same is happening.Shortly: you move the mouse to the locations side - it lags.When you move to the point where there is no location with objects - it doesn’t lag.
Maybe the solution is in optimizing,maybe i am wrong.Does anyone know about this problem?

Having a lot of objects placed in the scene will lag Unity, or rather, any game engine. The solution is either improve your hardware or lower your object count.

The number of objects should be causing a certain amount of lag but definitely not the main problem here. I found the answer here, try this and see if it solves yours: