If you are using Chrome, and experiencing slow-downs when viewing icons in the [more] category, you should enable GPU Rasterization.
To fix the issue in Google Chrome, do the following:
1) Load chrome://flags in the web browser's address bar.
2) Search for GPU rasterization. Alternatively, load chrome://flags/#enable-gpu-rasterization directly.
3) Switch its state to enabled.
4) Restart Google Chrome.