"If you know how to tread, bottomlessness need not concern you."
Tar baby is a doll made of tar and turpentine; it was used to entrap Bre'er Rabbit in an Uncle Remus story. The more the Rabbit fought the tar baby the more entangled he became. Tar baby also refers to a "sticky situation," where the only solution is separation.
The novel examines the complications of relationships: between whites and blacks, blacks and blacks; between gender and age; between ancient properties and contemporary mores. By interweaving contemporary scenes and myths, Toni Morrison raised the issue on the inability of blacks to unschackle themselves from the psychological echoes brought about by the past.
This might be one of the accessible novels of Toni Morrison, but definitely not very easy to interpret.