This question already has an answer here:
I've got a Polypropylene 630V capacitor.
Wikipedia says this about polypropylene in capacitors: "Very thin sheets of polypropylene are used as a dielectric within certain high-performance pulse and low-loss RF capacitors."
So, it is likely a "high performance pulse capacitor".
Wikipedia says this about pulsed powre: "Pulsed power is the science and technology of accumulating energy over a relatively long period of time and releasing it very quickly, thus increasing the instantaneous power."
Does this mean that: if I charge this capacitor with , say: 12V DC power supply 7Ah (my sealed lead acid battery) for long enough time, It could store enough charge to release hundreds of volts of electricity quickly?