Explanations

On the video he mentions the song: The book is on the table.

On the video he also uses the expression "on my behalf", this is what it means:
in behalf of For the benefit of; in the interest of.
on behalf of As the agent of; on the part of.
Both meanings are quite similar, so the expressions are sometimes interchangeable, but if we want to be strict, they mean different things. In behalf of means "for the benefit of," (e.g. we raised money in behalf of the hurrycane victims). On behalf of means "as the agent of, on the part of" (e.g. The guardian signed the contract on behalf of the minor child).

You can learn a bit more about prepositions of place here: prepositions of place. At the end of the page there is a quiz to test your prepositions and also links to more prepositions.