Yes the security patches are very less in size ... the google security patch is literally like 6mb or something ... then samsubg has to optimize that for its ONE UI ... so the update goes for 14mb ...
The bigger updates we get is bcz if the big fixes, app optimization, devive stability optimization, camera features etc ....
Even i was surprised to see this small update in a samsung phone. Generally i see such small updates in Nokia and Moto devices cz they use stock Android.
