Using a Decision Table in a Rule 
Procedure
Locate the ruleset (Where is my ruleset?), expand the ruleset node, the Rules folder and double-click a rule node.
or
Locate the flow ruleset (Where is my flow ruleset?) , expand the flow ruleset node, the Rules folder and double-click a rule node.
In the rule editor, in the Then section, choose the
(Add a new condition).In the drop down menu that appears, expand the Evaluate Decision Table node and choose the decision table name, you want to use in the rule.
NoteYou can dynamically invoke a decision table by choosing the variable definition instead of the decision table name.
More Information: Dynamic Invocation of Decision Tables
End of the note.Save the changes.
Result
During the execution of the rule the decision table gets evaluated.