The Table Defaults tab indicates the default tablespace that is associated with a DB Alias. The default tablespace varies according to the database management system.

A default database is required only for DB2® MVS™. Enter the default database appropriate for the DB Alias.
Enter the default tablespace, dbspace, or segment appropriate for the DB Alias. Click the arrow to select from a list, or select <DEFAULT>.
Select the check box to use the default parameters in all cases, or clear the check box to use source information from the Extract or Archive File.
Allocation Percent allows the adjustment of storage-related parameters on Create Table and Alter statements for tables. The allowable range is 0 - 999. The default value is 100. Allocation Percent is required only for Oracle databases.