Hello @AnthonyS,
           There are a couple of ways to acheive what you want. 
1. By using the JMP Scripting Language (JSL) 
2. By using the click and point interactive interface in JMP 
 
           I will show how to do both in my response and feel free to ask any questions. 
Approach 1 : 
// Open Sample Data Tables 
dt1 = Open( "$SAMPLE_DATA/Air Traffic.jmp" );
dt2 = Open( "$SAMPLE_DATA/Airline Delays.jmp" );
// Join Tables 
dt3 = dt1 << Join(With(dt2 ),
					Select( :Airline, :Carrier Code, :Flight Number, :Tail Number ),
					SelectWith( :Arrival Delay, :Distance ),
					By Matching Columns( :Airline = :Airline ),
					Drop multiples( 1, 1 ),
					Include Nonmatches( 0, 0 ),
					Preserve main table order( 1 )
				 ); 
Approach 2 : 
When you open a data table in JMP, navigate to Tables > Join , when you click on the Join you will see the following screen - this enables you to chose the tables with which you want to perform the join and also allows you to select columns for the joined table. 
 


					
				
			
			
				
	Best
Uday