It took me well over a dozen matches to get at least 10 kills. Throughout all the matches I never saw someone on the imperial side get over ten as this game type is very heavily weighted in the rebels favor as they have much better ships, much better abilities, and a much better hero. Now it's possible to get this in just a normal starting ship but you're going to get very close to the end of the match when you get near ten kills. What I did was at the start of each match I'd fly around near the bottom of the map looking for the hero pickup which will always be the millennium falcon. If you get it right at the start of the match you shouldn't have a problem getting ten kills.
-You can ram through enemy ships instantly killing them without taking damage (including Slave I if your shields are active)
Make sure to ignore the AI altogether (you can tell an AI based on whether or not there's a name above the ship and a tie interceptor will never be an AI).
- When a transport pops up wait a few seconds and then go to it as almost everyone in the match will be over there.
-Dont give up you'll get it eventually
- The hero pickup looks just like all the other pickups but with this symbol.
-Ignore the opposing hero. If you get wrapped up in fighting him there's no way you'll end up with ten kills.
Edit: This is also possible with Slave I if you grab it right at the start of the match.