Inconsistent memory usage between luci web interface and top command

I have recently installed OpenWrt and the memory usage shown in luci web interface is abnormally high.


However, the output of top contradicts with that.


(The new user restrictions prevented me from posting this as an image)

So, my question is: how much memory is actually being used?

This is a fresh installation so I have no idea where did this difference come from, any help would be appreciated!

Can you please post the complete LuCI memory section (instead of only one line)?