The Preview tab lets you explore a selected item's data without first having to create a map. You can examine the selected item's data in either Geography, Globe, 3D, or Table view. Geography view is the default. For items that contain both spatial data and tabular attributes, you can toggle between the views using the drop-down list at the bottom of the Preview tab.
Table view presents all rows and columns and the value for each cell in the selected item's table. You can explore the values in the table using the scroll bars, buttons at the bottom of the table, and shortcut menus that are available from the column headings.
You can find out if a data source has a specific attribute or if its values are correct. You can sort a table's records by the values in one or more columns, get statistics describing a column's values, or locate a specific value in a table. When exploring values, you can easily add and delete fields without having to open the data source's Properties dialog box.
Looking at tabular data in ArcCatalog
If you preview a table in ArcCatalog, you will always see your table just as it is set up in your database. All fields are visible, and you won't see any field aliases. For example, the field containing the property ID number is shown as PROPERTY_I. You can turn field aliases on by clicking the Table Options button and choosing Show Field Aliases.