Only just read this thread. Well done Will, I knew you would get there
If I can offer a couple of tips.
First I agree you have improved your opening statement. You now say
"Hello, my name's Will and I'm the magician tonight. Would you mind if I join you for a few moments? Have you seen much magic before..."
Still it can be improved further. When you ask whether they mind if you join them for a few minutes, you are making it too easy to say no, even though you probably don't pause much after asking that question to give much time to respond. Better though not to even ask it, just assume it unless they give you reason to believe otherwise.
Secondly rather than saying have you seen much magic, a slight adaptation by saying have you seen magic close up before, is likely to get a "no" and leads you perfectly in to showing them some.
So your opener could be this,
Hi, is everything ok here? ( pause and smile and they will probably assume at this point that you are management, sometimes I have a few minutes chat here ) great! well my name is Will I'm the resident magician here at *****, have you ever seen magic close up before? ( they say No or if yes you can ask them about it ) Ok well I tell you what I'll show you a couple of quick things while your waiting for your food, actually I'm going to show you something rather strange......
Remember this whole opener is about getting into rapport with the customers, if you do this properly they are much more likely to be good spectators.
Secondly all your effects are card magic, some of the best table magic is not card stuff and in actual fact if people have a negative belief about magic it will most likely be due to some uncle showing them c*** (not the best) card tricks. Therefore it's best to open with a non card trick and in my opinion not do more than 50% of your effects using cards.
But hey, you got in there and I'm sure you will develop your own style. You've done the hard part Will just go out there and enjoy:)