This story is a metaphor of the Christian Life.
The old man (tree) has passed.
The fallen tree being made into a table stands for when the person has trusted in Jesus as their Savior.
The fallen branch and birds nest shows that God still Cares for the person even though they have not yet trusted in Jesus as their Savior.
The full grown tree stands for when the person is an adult.
The sapling stands for when the person has grown into childhood.
The acorn stands for when the person is a baby.
This story is a metaphor of the Christian Life