There is no weight limit on an EASA (or UK) PPL. It is theoretically possible to add a type rating for any multi-pilot aeroplane but one would first have to hold or have held a MEIR, pass the ATPL examinations, complete an MCC course and an advanced UPRT course. Since no insurance company would be likely to provide cover for a PPL to actually fly such an aeroplane and, in any case a PPL could not fly one in a commercial operation or for remuneration, it seems an awful lot of work for little or no benefit beyond bragging rights.