Removing a Condition 
After you create a decision table, you can remove conditions in a decision table.
Note
You cannot remove all conditions. Decision tables must have at least one condition.
Locate the ruleset (Where is my ruleset?) , expand the ruleset, the Decision Tables folder and double-click a Decision Table node.
or
Locate the flow ruleset (Where is my flow ruleset?) , expand the flow ruleset node, the Decision Tables folder and double-click a decision table node.
In the decision table editor, choose the Condition button.
In the menu that appears, choose Remove Conditions.
In the dialog box that appears, select the conditions that you want to remove and choose OK.
Save the changes.