I am working with a data table and displaying the resulting chart.

My current situation

A data table was created by using index function to populate data from SharePoint lists .  

Since the SharePoint site is updated frequently, do I create this table with enough allowance for expansion or just one to match the current items in the table. If I just create a table to match the current items and when it refreshes with new data, will the table expand and will the index formula function also expand into the new rows? 

Any insights would be appreciated.

Thanks-Bill