In this step of the wizard, you can choose the data to merge. You can select from different input files and layers.
In the Data Merge Wizard, click Browse.
In the File Selector window, select the file you want to add and click Open.
If you want to view the properties of a file, right-click the file in the Available Files/Layers list and click Properties.
In the Available Files/Layers list, enable a check mark next to any layer that you want to add as an input layer.