decision table	-	-	-	-	-	-	-	-	-
have milk	N		Y
have cereal		N	Y
hungry			Y

get milk	X
get cereal		X
eat			X
re-enter table	X	X

There are basically four parts to a decision table.

condition stubs	condition entries
action stubs	action entries

Each line in the condition stubs is a IF type test. The rest of the row are the condition entries associated with that condition stub. Each of the action stubs specifies an action to be performed. It is performed if the action entry is marked for the column that is selected. A column going from the condition entries to the action entries is called a rule.