Hello and hope you are doing well.
Usually athletes and people who tend to be very active physically have low blood pressures and pulse rates, this is because the heart is that much more efficient to pump blood effectively. Normal Blood pressure range is Systolic BP: 90-139mmHg, Diastolic BP: 60-89mmHg and Pulse rate: 60- 99 beats/min.
Hope this helped and do keep us posted.
Great the way the heart adapts isn't it. Your fitness regime (lawn tennis) has caused your heart to become more efficient.
You have a great bp. Almost good weight, Pulse rate is fine! Only if it would go under 40, would be a problem. Keep playing!:)..but keep an eye on those pulse numbers.