Xenia's tablet is the black square at the left of the table. When you pick it up, you see only six boxes with locks on them and one with a question mark. Click on the question mark to find --
Hint 3
-- a sort of jigsaw puzzle. Read to the end of this hint for a picture of the completed puzzle.
Hint 4
The pieces are on the right; left-click to pick one up and put it in place. They're all right-side up and don't have to be rotated. When a piece is put in the right place, it clicks and can't be moved again.
Hint 5
If you don't see any pieces you can place, use your mouse's wheel to scroll through the list and find one you recognize. I usually start with the top border, which is quite recognizable.
Hint 6
The completed picture, which is four women in long robes looking decorative, looks like this: