The literal meaning of Bonseki is Bon = tray and Seki = stone, and it is one of the traditional artworks in Japan.
On a black tray, a couple of natural rocks are put to represent mountains and white sands are sprinkled, and some feathers are used to create flows of water and waves so that they express the grandness of the sea and rivers.
Bonseki has a long history. The origin of it was already seen on an incense burner given to the Emperor Suiko from Kudara back in 6AC.
(Kudara is a country in 4AC-660AC in the West and South-West of Korean peninsula)
Bonseki was the way to express the sence toward the nature by ancient Japanese people who loved the nature, lived with the nature and united the nature with their life.
According to a Bonseki teacher who demonstrated at the exhibition of Bonseki, the traditional sence of beauty of the Japanese is `not to fill in all of the spaces`, which is seen in Bonseki.
For more detail, here is the link (written in Japanese).