Up to 6 columns out of the box.
When you add a new row, you will be presented with the following options, which will allow you to choose your column structure. As you can see, you can select up to 6 columns layout on a single row. Depending on the Section type you select (Regular section or Specialty section) you will see two types of available column structures:
Need more than 6 columns?
You can follow this tutorial to use as many columns as you like: