PPL student here, studying airspace. Looking at the airspace around Vancouver, BC (see Vancouver VTA) I see that most of the lower mainland is class E controlled airspace. "No Contact" tells me that there is no ATC unit to ask for permission. Why is it class E then in the first place? Why isn't it class G?
In class E airspace, ATC service is provided to IFR flights, but not to VFR flights. The "NO CONTACT" note most likely refers to VFR flights, since you are looking at a chart designed for VFR flight planning. The airspace is class E, and not G, because whoever designed it wanted IFR flights to be controlled within in.
See this related answer for a brief description of the different airspace classes.