The performance tables contained in the kneeboard were written by the aircraft manufacturer basing on data recorded on a full loaded airplane with a specific Center of Gravity (C.G.) position.
This means that if you are flying with a different plane load or with a aft/forward C.G. the resulting speed may differ a little (few knots) from the one reported in the tables.
← The plane is faster (or slower) than reported in the performance tables