A rocket upper stage, sometimes called kick stage, is the last stage of a rocket and it is used to deploy satellites in orbit.
A space tug is a spacecraft released from the upper stage and it is used to transfer a satellite from one orbit to another orbit.
Some space tugs can deploy multiple satellites at once, and then they are called "satellite dispenser".
The upper/last stage (or kick stage) of a rocket can be considered a satellite dispenser. But I'm not counting those.
The first satellite dispenser I can find is Moog Inc. that launched a satellite dispenser (does it have a name?) on a Falcon 9 rocket on 14 July 2014.
Is there any satellite dispenser launched before that?
SHERPA is another satellite dispenser that was launched in 2018
+1
for the edit, thank you! When people ask for clarification it's (usually) really meant in good faith. Even though it may feel completely clear, everybody is different. The goal is to ensure that the question is clear to the widest possible audience. What I've found after asking well over 2,000 Stack Exchange questions is that 99% of the time if someone asks for a clarification, no matter how silly or strange it feels to me, if I just go ahead and clarify everything works out well. $\endgroup$