#AtkTable should be implemented by components which present elements ordered via rows and columns. It may also be used to present tree-structured information if the nodes of the trees can be said to contain multiple "columns". Individual elements of an #AtkTable are typically referred to as "cells". Those cells should implement the interface #AtkTableCell, but #Atk doesn't require them to be direct children of the current #AtkTable. They can be grand-children, grand-grand-children etc. #AtkTable provides the API needed to get a individual cell based on the row and column numbers.