SQL> create or replace procedure 
  2  n_test(table_name in user_tables.table_name%type) is
  3  type emptabtype is table of emp%ROWTYPE;
  4  emptab emptabtype;
  5  begin
  6  EXECUTE IMMEDIATE 'SELECT * FROM ' || table_name 
  7  BULK COLLECT INTO emptab; 
  8  FOR i IN emptab.FIRST..emptab.last
  9  LOOP
 10  dbms_output.put_line('Employee name = ' || emptab(i).ename);
 11  END LOOP;
 12  end;
 13  /

Procedure created.

Elapsed: 00:00:00.40
SQL> exec n_test('emp');
Employee name = SMITH
Employee name = ALLEN
Employee name = WARD
Employee name = JONES
Employee name = MARTIN
Employee name = BLAKE
Employee name = CLARK
Employee name = SCOTT
Employee name = KING
Employee name = TURNER
Employee name = ADAMS
Employee name = JAMES
Employee name = FORD
Employee name = MILLER

PL/SQL procedure successfully completed.

Elapsed: 00:00:00.06

SQL> declare
  2   tabname varchar2(10) := 'emp';
  3   rc sys_refcursor;
  4   ename emp.ename%type;
  5  begin
  6   open rc for 'select ename from ' || tabname;
  7  end;
  8  /

PL/SQL procedure successfully completed.

SQL> declare
  2   tabname varchar2(10) := 'emp';
  3  begin
  4   execute immediate 'update ' || tabname || ' set ename = upper(ename)';
  5  end;
  6  /

PL/SQL procedure successfully completed.