There is a book on the table, with which bodies does it interact? Why does the book stay alone?

The following forces act on a book lying on the table:

Gravity Ft, equal to m * g (where m is the mass of the book, g is the acceleration of gravity.). This force characterizes the interaction of the book and the Earth;

The force of reaction of the support N, numerically equal to the force of gravity in this case, this force characterizes the interaction of the book and the table;

The book is at rest, because the above forces are in balance, that is, they mutually balance each other.