How to find which tables were deleted (in Oracle)
If you have the recyclebin turned on in your database you can query the DBA_RECYCLEBIN view to find which objects were dropped within a certain time period.

SELECT owner,
       original_name,
       operation,
       droptime,
       can_undrop
FROM   dba_recyclebin
WHERE  TO_DATE (droptime, 'YYYY-MM-DD:HH24:MI:SS') BETWEEN SYSDATE - 3
                                                       AND SYSDATE


You can issue a FLASHBACK command to restore the table;

FLASHBACK TABLE &lt;you table's original name&gt; TO BEFORE DROP


Alternatives are to flashback to a specific SCN, TIMESTAMP, etc.

See https://docs.oracle.com/cd/B28359_01/server.111/b28286/statements_9012.htm#SQLRF01802 and http://docs.oracle.com/cd/B28359_01/server.111/b28310/tables011.htm#ADMIN01511 for some more reading (it never hurts to read)