Does lacquer coat protect a PCB from ESD damage?
Yes and no.

Yes:  It is possible to cover a PCB with something like lacquer and this would offer some protection.

No:  The protection that lacquer offers is not enough.  Not even close, actually.

The lacquer would protect the PCB from a direct zap to its circuits.  The issue is that direct zaps are not usually the problem.  The problems that ESD causes are usually from zaps to the cables and connectors (which cannot be covered in lacquer), or due to induced spikes on the wires from nearby ESD zaps.  

In the latter case, lets say that you touch a door frame and it causes a zap.  That zap will radiate lots of RF energy which can get picked up by cables and traces on the PCB.  Those cables and traces act as an antenna, receiving the RF energy that the zap creates.  If the zap is strong enough, or close enough, it can cause things to not behave correctly.  I have seen badly designed PCB's die from a static zap 8+ feet away.   Lacquer won't protect from that.