Rule12f says that we may strike from a pleading. Can a Motion to Strike be used to strike matter from a memorandum in opposition to a Motion for Summary Judgment? On Jurisdictionary, it is stated that a Motion to Strike can be used on pleadings or "other forms".

If any of the grounds stated in the rule apply to facts or law alleged in the memorandum, filing a motion to strike on one of those grounds may be a good idea ... especially if it tends to make your record!