When setting a watch on <object>.COUNT, it does not show the value of the count.
Create a variable and set that to hold the value of <object>.COUNT.
Set a watch on that variable so that it will display the count when that line in the script is run.
Sample:
PROCEDURE var_table_proc
AS
TYPE table_varchar IS TABLE OF VARCHAR2 (20);
var_table table_varchar;
temp int := 0;
BEGIN
var_table :=
table_varchar ('1',
'2',
'3',
'4',
'5');
temp := var_table.count; -- set the watch on temp
END;