OK, the tray seems to have no special meaning. It is just a gift for you.
The panphlet is from the vender of the tray saying,
> Thank you for buying our product.
> To keep the tray beautiful forever, wash it with warm water and wipe it with soft cloth after use.
> Scrubbing brush, powder should not be used to clean it.
> If bland new tray smells, soak it in worm water for a while.
The vender of the tray is "Bunaco"
http://bunaco.jp/ and you can see how it is made in bunaco here
What's BUNACO .
RK