why capacitor connect serially with resistor on the earth pin
The resistor's there for your safety

Static-dissipative grounding apparatus (such as wrist straps and mats) will always have a high-value resistor between you and the metallic connection to the earthing system.  This is because most of the time, you will be connecting this to the mains earth in your building via a mains receptacle, and a direct connection could prove quite disastrous if you connected to an improperly wired receptacle (where the ground terminal on the receptacle was connected to something other than a ground wire).

The other component is indeed most likely a polymeric-PTC resettable fuse, by the way.  (Many static-dissipative setups get along just fine with resistors alone.  I can't tell from here if they added it due to concern about resistor power or voltage ratings, or for personnel-safety reasons, though.)