# Working with Table Views
Most input data required by GSA can be entered in tables. Tables in GSA are similar to spreadsheets, but there are a number of significant differences. These are highlighted in the sections below.
The shaded cells across the top of a table contain default values, which can be changed by the user. These are placed in the current cell when the cell contents are entered as blank.
Note that some Cell operators operate with default values.
For many of the tables there is the option of defining the data in a Wizard. The wizard is available from the Wizard button in the Data Options toolbar, or from the table context menu or with the shortcut Ctrl+W. The use of wizards is necessary for some of the modules where it is not otherwise possible to select or set up the required data.
Changes made in a table are immediately reflected in other tables, Output Views and Graphic Views, and vice versa.
Note that in general, data cannot be entered or edited if results exist that would be invalidated by the changes.
The details of the data entered in each table are covered in the Data in GSA section.