Oracle Alerts back end tables and it is description

ALR_ALERTS -  It stores the alerts definition and the query
ALR_PERIODIC_ALERTS_VIEW -- It stores the periodic information of an alert
ALR_ACTIONS - It stores alert action information, ex. email subject, body and other infromation
ALR_ACTIONS_V -- It is a view based on ALR_ACTIONS

Adding a form function to menu or submenu using back end script

DECLARE
   xrowid   VARCHAR2 (2000);
BEGIN
   fnd_menu_entries_pkg.insert_row (
      xrowid, -- Rowid
      87216, -- Menu ID
      201, -- Sequence Number
      NULL, -- Sub menu ID
      50138, -- Function ID
      'Y', -- Grant Flag
      NULL, -- Prompt
      NULL, -- Description
      SYSDATE, -- Creation Date
      -1, -- Created by
      SYSDATE, Last update date
      -1, -- Last Updated by
      -1 -- Last update login
   );
   COMMIT;
EXCEPTION
   WHEN OTHERS
   THEN
      ROLLBACK;
      DBMS_OUTPUT.put_line (SQLERRM);
END;

What is difference between AD_BUGS and AD_APPLID_PATCHES ?

AD_BUGS holds information about the various Oracle Applications bugs whose fixes have been applied (ie. patched) in the Oracle Applications installation. 

AD_APPLIED_PATCHES holds information about the "distinct" Oracle Applications patches that have been applied. If 2 patches happen to have the same name but are different in content (eg. "merged" patches), then they are considered distinct and this table will therefore hold 2 records.