What is the way to clear logics for the kid? For example how to make sense for the kid as what tables (mathematics) are?

The best way to clear logic is by giving examples from day-to-day life which the kids can understand and are able to relate to. Everyday, every class they get introduced to new things, subjects, experiences. Kids these days are much more smarter and want appropriate logic for everything. If you want to explain tables, for eg., the best example would be showing them multiplication with chocolates or biscuits and how the repeated addition is actually multiplication! Whenever you are doing something and it is related to a subject, immediately explain your child the logic with that example. For eg..if you are teaching articles, ask them by examples which article should be used where.. Make learning a fun for the kids, not a task!