Currently, I'm trying to pass a resultset to a Table helper in order to return a table that gets added to a panel within a tabbedpane. When I launch, nothing shows except if I add the returned table to a JOptionPane and then it works fine. Not sure what I'm doing wrong as I normally do not work with swing
Just because you give the instance field a different value, doesn't mean that the current table gets replaced. Remember, variables to objects are actually variables to references. By changing the value you're just letting the variable refer to a different object. The original object still remains the same, and that's what's being used in your UI.
Change the method to return a TableModel, and then call table.setModel(JTable_Helper.buildTableModel(rs));. This will set the model (backing data) of the existing table to your new table model.