SQL> CREATE OR REPLACE PACKAGE emp_package IS
  2    TYPE emp_table_type IS TABLE OF emp%ROWTYPE
  3      INDEX BY BINARY_INTEGER;
  4  PROCEDURE read_emp_table
  5                     (p_emp_table OUT emp_table_type);
  6  END emp_package;
  7  /
SQL> package created

SQL> ed
Wrote file afiedt.buf

  1  CREATE OR REPLACE PACKAGE BODY emp_package IS
  2    PROCEDURE read_emp_table(p_emp_table OUT emp_table_type)
  3    IS
  4    I BINARY_INTEGER:=0;
  5    BEGIN
  6       FOR emp_record IN (SELECT * FROM EMP) LOOP
  7       emp_table(i):=emp_record;
  8       i:=i+1;
  9       END LOOP;
 10    END read_emp_table;
 11* END emp_package;
 12  /

Warning: Package Body created with compilation errors.

SQL> show err
Errors for PACKAGE BODY EMP_PACKAGE:

LINE/COL ERROR
-------- -----------------------------------------------------------------
7/6      PLS-00201: identifier 'EMP_TABLE' must be declared
7/6      PL/SQL: Statement ignored

 CREATE OR REPLACE PACKAGE emp_package IS
TYPE emp_table_type IS TABLE OF emp%ROWTYPE
INDEX BY BINARY_INTEGER;
emp_table emp_table_type;--you are missing this
PROCEDURE read_emp_table
(p_emp_table OUT emp_table_type);
END emp_package;

CREATE OR REPLACE PACKAGE EMP_PACKAGE
IS
  TYPE EMP_TABLE_TYPE IS TABLE OF EMP%ROWTYPE INDEX BY BINARY_INTEGER ;
  
  PROCEDURE READ_EMP_TABLE(P_EMP_TABLE  OUT EMP_TABLE_TYPE);
END;
/

CREATE OR REPLACE PACKAGE BODY EMP_PACKAGE
IS
  PROCEDURE READ_EMP_TABLE
       (P_EMP_TABLE  OUT EMP_TABLE_TYPE)
  IS
  BEGIN
    SELECT *
    BULK COLLECT INTO P_EMP_TABLE
    FROM   EMP;
    
    FOR I IN P_EMP_TABLE.FIRST.. P_EMP_TABLE.LAST LOOP
      DBMS_OUTPUT.PUT_LINE(P_EMP_TABLE(I).ENAME);
    END LOOP;
  END;
END;