How to fix lag on mobile

I decided to see how Unreal Engine 4 performs on a tablet and for that I created an empty world with a cube in the middle and 1 point light point at the cube from far away. Also, there is a 256x256 brick texture on the cube and no maps. When I look at the cube from far away everything is fine - 60 fps. However the closer I get to the cube and the more of the screen it covers the less FPS I get. It gets to the point where I have ~10 FPS. I have tested this with a skybox and I’m stuck with ~12 FPS regardless of where I look (even the bottom part of the skybox, which is pitch black). What is causing this and how do I fix this?

The tablet is Google Nexus 7 2012 version.