If you are using 10g/11g, the table might be in the recycle bin. Otherwise you either have to restore the whole database to a point in time before the table was lost, or restore to another location to a time before the table was lost, and export the table. How you recover depends on how that table fits in with your application. i.e. If there are foreign keys you have to make sure that the data is there and the foreign keys are enabled again.