balls aren't cheap and there are some people on the board here that might know that table better than me, I could figure it out if I played on it but...all that to say, try some different balls
those look lite (weight) and small - the light weight on a textrued surface would also make them that much slower
try a Dynamo ball, a Warrior ball, and an old pink Tornado ball - Dyno is heaviest, then the pick Tornado, and the Warrior is much lighter but it is a terrific ball...I don't know how it would play on that table
again, others may know a better ball(s) for that table
good luck and have fun...if you get all caught up in it, and decide you want to get a good table, come back on line here first and we can help you with what to get
what city state you in? have you seen local "tournament" foosball before? be good to get you hooked up there if you have something close