Charles Ellicott Commentary Genesis 10:32

"These are the families of the sons of Noah, after their generations, in their nations: and of these were the nations divided in the earth after the flood." — Genesis 10:32 (ASV)

After their generations. —Hebrew, according to their Tôldôth. This makes it probable that each family preserved in some way an historical record of its descent; and as this table is called the Tôldôth of the Sons of Noah, it was probably formed by a comparison of numerous Tôldôth, each showing the descent of various members of the three great families into which the sons of Noah were divided.