The types marked red are not in use. Hence you can ignore these alphabets. It is but natural that Tamil parents, why for that matter any parent would like his or her children to acquire the skill to read and write in their respective mother tongue.
Children learn to speak in their mother tongue by merely listening to their parents and relatives.
But learning to read and write in a language is another matter. These skills can be learnt only with outside help. To expect the provincial authority to provide facility for children of other provinces living in their province to learn their mother tongue is impossible. Hence parents living in states outside their own, will have to make their own arrangements to teach their children their mother tongue. Since the parents do not find the time and besides it is very difficult to get tutors to teach one's mother tongue in states other than their own, the need for a 'self learning' reader is imperative.