There are 8 chairs on each side of the table. Let the sides be represented by A and B. Let four persons sit on side A, then number of ways of arranging 4 persons on 8 chairs on side $A = ^8P_4$ and then two persons sit on side B. The number of ways of arranging 2 persons on 8 chairs on side $B = ^8P_2$ and the remaining 10 persons can be arranged in remaining 10 chairs in 10! ways.
Hence the total number of ways in which the persons can be arranged
$=^{8}P_{4}\times^{8}P_{2}\times10!=\frac{8!\,8!\,10!}{4!\,6!}$