Creating tables is normally done in one of the following ways:

  1. editing an Excel file
  2. editing via the UI using the Model Page Editor.
  3. editing via the UI using the Gridview Editor.
  4. from existing data using the Data to Model feature
  5. extracting the xMart table definition using a query from a SQL Server database.

If you are creating the model yourself, it’s a good idea to read Best Practices and Data Modelling Basics.