They are two separate instruments or instrument families, each played with a separate hand. The "tabor" is a snare drum played with one stick and secured to the arm, which is
…a percussion instrument, and the "pipe" or "3 hole pipe" is a specific type of fipple flute, which is a specific type of woodwind. The "pipe" is different from other fipple flutes because it has only three holes and relies on overtones heavily. There isn't much to say that a "pipe and tabor" refers to any specific pair of instruments beyond this, which means that it really is two families of instruments, not necessarily a specific drum and woodwind. Examples of "pipes" include the English tabor pipe, txistu, and fujara. Sources: Wikipedia and The Taborers Society website (MORE) 
