These are the numbers of chocolate bars that each party guest has at the time she sits down:
A=3, B=2, C=1 1/2, D=1, E=1, F=1, G= 3/4, H=2/3, I=3/5, J=1/2, K=1/2, L=1/2, . . . .
Notice that when D sits down, she can sit at any table and would get 1 chocolate bar. So while different people may have different table arrangements, these numbers should be the same for everyone.
Can you find a pattern? If you can, then you could start to explore larger numbers, such as where does the 100th person sit?