You can selectively hide or show fields in the Data window. To hide a field, right-click the field and select Hide.
When you want to change your fields from hidden to visible, select Show Hidden Fields on the Data window menu.
The hidden fields are shown in gray in the Data window. You can then select one or more hidden fields, right-click and select Unhide.
Select Hide All Unused Fields on the Data window menu to quickly hide all of the fields that are not being used in the workbook.