There is a tablet here - and a very non-puzzly note addressed to Indy. It reads:

How are you doing? It's been pretty busy around here. I got hired by some weird bank to track down these ancient tablets. Fun mission! But listen, I wasn't sure about their motives, so I decided to put it someplace more safe. Glad you were able to follow the trail I left you.


After examining the tablet, Indy tells you:
This tablet seems to be some sort of calendar system. It looks like records - or possibly even predictions - of events. Maybe we can decipher it and find some *real* treasure! I think we need more than one tablet, though.