There are many ways to save yourself from repetition in ArcGIS, most of which rely on stringing together geoprocessing tools and clicking a "Go" button. You can do this using ArcObjects (personally, I wouldn't bother), Python script, ModelBuilder, or batch processing (listed in my order of most flexible/hardest to learn to least flexible/easiest to learn). You need to decide which road you feel like going down.
The main tool(s) you're looking to repeat are Add Join or Join Field.