I’m experiencing same issue and would like to point out another thing:
when I create a new project (any type) and add camera actor to the scene, editor memory usage jumps up. It’s obviously caused by preview viewport of the camera but when I deselect the camera, memory doesnt drop, it stays on the same level for w while and then begins to grow, just like normal_ST described. Although, my editor is eating memory even without any blueprints/ai editor tabs open.