Alright folks, here's my take on the whole thing.
We know that the scrolls have symbols on their ribbons:
We know that the tablet symbols match the symbols on scrolls:
And we know that the some of the doorways in the 1000 tombs have symbols above them:
I think this is like the one tower in Kirby's Dreamland 2, where you have to use certain powers to open doors, and you're given a selection of three doors. You can only open one door per room, and continue on from there. Once you get to the top of the tower, you wind up in a room with a Rainbow Piece, but it will be blocked such that you can't reach it. It's not until you realize that you have to use the Spark Ability with Kine to produce a lightbulb in a dark room earlier on in the level to light up a wall which shows you the sequence of powers to use to open doors than you can figure out the proper combination such that you wind up being able to access the Rainbow Piece.
All that being said, I think the tablet is a map. You need to fill in the entire tablet so you can follow the symbols above the doors to some special room or something. There's times when there are multiple doors with the same symbol, but if you go the right way, I bet each symbol would only show up once.
Or maybe I'm just goofy.
Edit: It turns out that the tablets are random with the symbols.