I believe the box to be Boite Nature. It was made by Benson & Hedges. There is writing on the lid of the box, as well as inside. It reads: By Appointment to His Majesty the King. Also on the sides of the box there is more writing. It reads: On the front, Invicible de B. & H.
It is a very heavy plate and is 14 1/2 " in diameter. It has blue etching around the rim, and a flower patch medallion inset in the middle which looks to be ceramic. The rest of the platter feels like Bone China with a cross hair pattern that gives the platter a sort of bamboo style look. I have not been unable to identify the signature.