Below is a situation

I have two database table

1: Posts

2: Recent Watched

Now What I want is whenever user visits a certain post of mine, then it will make a new entry into recently watched table, through which i can see recently watched posts

Now The Problem is If my website hits reaches more than 200 k, then this table will be filled with no of records and ultimately will make my database very heavy

Now what I want is to delete the records from this table when it reaches certain limit automatically without any manual interference