Unfortunately, an A4 booklet is too big for the treasure chest. An A5 booklet, on the other hand, fits in easily.

no, unfortunately an A4 booklet does not fit in the treasure chest

No. The inside dimensions of the base are 18.5 X 36.5cm
Outer dimensions measured at the bottom edge: Width 39cm, depth 20cm, height 22cm

In length yes, but not in width. If you roll it, it fits.

Not lying down. But if you stand it up a little, it fits.

Hello
Yes, actually it is. Just not completely smooth.