The problem comes when the icon that it defaults to for printing is a right load, but the only way that envelopes can be loaded is in the center of the tray. I have an HP Colorlaserjet 3600 and an HP Officejet Pro 8600 and both load this way.
A technical definition of a function is: a relation from a set of inputs to a set of possible outputs where each input is related to exactly one output.
A math function table is a table used to plot possible outcomes of a function, which is a kind of rule. The table results can usually be used to plot results on a graph. To fully understand function tables and their purpose, you need to understand functions, and how they relate to variables.