If I may offer an alternate explanation...
I believe the second deck reads "P Gow 2". Pai gow poker is a fairly popular casino game, particularly among Asian players. Casino decks, particularly for games where the players actually handle the cards themselves, are frequently changed so as to prevent marking and other forms of cheating. When a deck is retired from play, it is sorted to ensure all cards are still present, then replaced in the box. The box is labeled with the time and date the deck was used in play, what game it was used for, and signed off by the boss in charge of the pit. The decks are often sold off in casino gift shops, though the cards are marked so they can't be brought back into play (typically by clipping corners or drilling a hole through the deck).
I'm afraid your signatures are only those of casino employees.
I might agree with that - in fact, I'm very inclined to agree with that - but one detail is off. Casino-used decks are usually named and are unique to that casino while these decks appear to be "Bumblebee" standard issue.
I'm going to guess that they were indeed table-used, but at a trade show rather than on a casino's gaming floor. It makes more sense, especially considering they bear markings of a chip-marking company that frequents such shows. They're not so much autographs as they are listings of the deck's statistics which got recorded just like on casino decks - date, dealer, etc. They probably had a few tables going in order to demonstrate their products in a real-world situation.
This especially makes sense when you factor in that Bumblebees are traditionally cut, just like pretty much every casino deck out there these days. I think USPC might have even been using them as sample decks for potential casino customers at the time; these days they use a standard deck box for off-the-shelf Bees and the standard Diamond Back, no Stingers, Bumblebees, etc. Bill Schulman gave me a handful of them a few years ago as a thank you for doing him a favor.
The dates make a lot of sense as well - paper poker-sized decks were still common at poker tables in the early-mid '90s. Most have shifted to plastic and bridge-sized by now.