Table Merger is a simple to use and free Adobe InDesign script which helps you to quickly and easily merge two tables.
One can select to either merge horizontally or vertically. To use the Table Merger script, select two tables and run it.
Installation: Open the "Scripts" panel in InDesign, select the "User" folder, select "Reveal in Finder" from the drop-down menu on the top right side. Copy the Table Merger script to the "Scripts Panel" folder in the opened window.