Is it normal for bpto fluctuate during change of activity from 103/70 to 133/86 just walking upstairs? I usually have low blood pressure but notice thse flucuations at home.

Normal for BP. Blood pressure varies throughout the day and with many factors such as exercise, pain, caffeine/nicotine and so on. Those numbers are fine. It is worth considering your fitness though, as some changes could be from not being in as good a shape as when younger.
Normal. When exercising, your muscles need more oxygen. The heart pumps more blood around your body with more powerful contractions that will make your blood pressure increase. Your systolic blood pressure increases during exercise as the cardiovascular system delivers more blood to the working muscles and your diastolic blood pressure stays roughly the same. Keep walking those stairs; it's great exercise.
Yes. Systolic BP (the top number) normally rises with exercise. Diastolic BP (the bottom number) does not change or may drop slightly.