This video demonstrates how to create a new table, Category_T, in an existing relational database (at 1:01), set primary key (at 1:31 and at 2:38), insert new records using "Edit Top 200 Rows" (at 1:58), set auto-incremented identifier (at 2:06), and add a one-to-many relationship between two tables: Product and Category using "Foreign Key Relationships" (at 3:48).