When you delete a workbook, all tables within that workbook are automatically deleted. However, deleting a single table should not cause the entire workbook to be deleted. The workbook should remain intact even if you delete individual tables within it.
If your workbook appears to be deleted, you can check your Archive (accessible from the top navigation bar) to recover your deleted tables. You'll need to restore each table individually to reconstruct your workbook.
Hey Enoch - When you delete a table, the workbook shouldn't get deleted - it may be the case that you deleted the workbook by accident. In either case - you should be able to find what you deleted in the trash: https://app.clay.com/workspaces/184042/trash
Let us know if you can't find it!