You can go on the Disney Gift Card website and combine funds from multiple cards up to a max of $1000 onto one card. So I think that what PP is doing is buying a fresh gift card from Disney Gift Store and then transferring balances from other gift cards on to the fresh one.
I usually buy wristlet gift cards either at Epcot or my resort gift shop (I just put a minimum amount on these) and then transfer funds from e-gift cards that I have purchased at a discount from Sam's Club or
Best Buy . These gift cards are plastic and not flimsy, and the wrist band makes them convenient to use.
I also never use a gift card at a table serve restaurant. What I did last time, was use my magic band to charge my meal back to the room and then I went to the front desk when I got back to my resort and used gift cards to pay down my balance.