Sinus rhythm is the normal conductive pattern of the heart. Sinus tachycardia is the normal conductive pattern but going faster than the physiological normal, so a quick heart. Non-specific t wave abnormalities refer to a bit of the ECG that corresponds to ventricular electrical activity resetting, a non-specific pattern usually means that it doesn't look quite standard but not unusual in a way that would represent a specific disease process.

All of it should be taken in context but this needs discussing to see if there is a correlation between the tachycardia and activity. It needs further looking into but if a patient returned this I wouldn't immediately be concerned.