Now that you have explored some of the possibilities for using excel at home, what concerns or questions do you have about using it?

This seems like an opinionated question, I suggest attempting to answer it yourself.

only #2 represents an object at rest on a table.

in #1, there is no normal force due to the table; the object is accelerating downward.

in #3, the vertical forces are not balanced; the object is accelerating downward.

in #4, neither the vertical nor the horizontal forces are balanced. the object is accelerating upwards and to the right.