Good (or lucky) choice.
Align Objects relocates a group of selected Objects to align them as directed by the menu choice. Choosing 'Top' means the top of each of the objects will be in the same vertical location on the screen.
If the objects to be aligned are all 'in the window', the alignment will likely move other selected objects up to match the top level on the highest object.
Going by your example, and its behaviour, the align action will apparently move any object that is partly outside the window (in this case, your table) back into the window before moving the other object(s) to align with the top of that table. Useful finding that, kept in mind, could be useful in future.
Regards,
Barry