Card OneThe remarks in the centre column refer to the War Service Increment (WSI) to which he was entitled for 3 yrs service, which he was paid with effect from 19.7.45 at the rate of 1/- per day
Card TwoACH/Driver stands for Aircrafthand Driver
The remarks on the right hand side are just his promotion details with, at the bottom, the percentages gained in the two trade related examinations he attended. Maybe Ross (RAFCommands) can explain the exact title of the exams. I think but am not certain, that LTTB stands for Local Trade Training Board
LAC is Leading Aircraftman; DMT is Driver Mechanical transport
Cpl is Corporal
Card 32 and 16 RC refer to Recruiting Centres 2 and 16, respectively, that is to say his basic recruit training.
He was then posted to
RAF Waddington in Lincolnshire (part of Bomber Command) where he was in 121 Flight of Airfield Headquarters (AFHQ)
This was followed by 6245
FlightService Echelon (see reply from RAFCommands below), part of Station Flight. 'Flight' is the term the RAF use to denote a subunit roughly equivalent to a platoon or troop in the Army. Usually commanded by a junior officer or Warrant Officer. In his case this would have probably been the Station MT flight.
Then after the war had ended he was posted to
RAF Sylt in Northern Germany.
Prior to his demobilisation he was posted to 101 Personnel Dispatch Centre (PDC) for final processing.
Let me know if there's anything else you don't understand