The ten china figurines on the dinner table allude to the "Ten Little Indians" nursery rhyme, which is framed on the wall of each bedroom. They also represent the guests on Indian Island who are being bumped off by a crazed killer one by one. Each time a guest is murdered, one of the china figurines mysteriously vanishes.
This is a useful plot device, as it helps to build suspense. The disappearance of the figurines scares the living daylights out of the guests, as it really brings home to them just how much danger they're in. The china figurines are almost like toys to the murderer, a crucial part of the sordid little game they are playing with their guests. And the murderer's removal of each figurine perfectly symbolizes the callous, manipulative manner in which the murderer treats their victims.