declare
  type tab_number_type is table of number index by binary_integer;  -- declare the array type
  v_tab_number  tab_number_type;  -- declare a variable of the array type
begin
  v_tab_number(1) := 123;
  v_tab_number(2) := 234;
end;

declare
  type rec_array_type is record(x number, y varchar2(10));
  type tab_array_type is table of rec_array_type index by binary_integer;  -- declare the array type
  v_tab_array  tab_array_type;  -- declare a variable of the array type
begin
  v_tab_number(1).x := 123;
  v_tab_number(1).y := 'Koala';
end;