This appointment will allow time for a discussion with a midwife councellor, a scan of your baby and an amniocentesis if you should request this.
I think this line is very important. You can go in and find out what your actual risk # is, which could be very helpful in your next step. It sounds to me like they have literally scheduled enough time for a talk, a scan and an amnio. You don't have to have any of those, but you can if you choose. It would be hard going forward knowing that your at high risk, or some version of that. Wouldn't it be better to know if it's very high or slightly high?
Also, on the side of the amnio, I think it's a valid point to stop and really think about. IF the amnio comes back positive for down syndrome, you will have so much more information to go forward with. This does not mean that you have to terminate or anything like that. Knowledge can be very powerful in an instance like this. The end of the line is delivery and at that point the "test" will be done. You will know at that moment if the baby has down syndrome or not. So, now or later, you will find out the answer. Not finding out now is only delaying finding out until later. FOR ME, we wanted to know sooner than later what we were dealing with, our results had many issues in them that could necessitate surgeries IF certain things were happening. We had to know if we qualified for surgery so we had to get the amnio (we had a cvs, same as amnio, just done earlier in pg).
Not that you asked, but my opinion would be to go and talk to your midwife (Honestly, you'll get these results next time you go in anyways I'm sure, they'll be on your records). Find out what your real risk number is, then do the scan! What can it hurt?! A free scan to double check the findings, a scan to just look and see if what they saw earlier confirms or denies anything. THEN if appropriate, talk about the amnio. Don't even think about termination at this point, it's not an option for you, but that doesn't mean you can't find out what your dealing with.
I hope I'm being clear, I know I'm not with the norm and I'm talking from an emotional position, but for me, knowledge is power and a scan can't hurt, why delay the results when you'll get them eventually anyways. Good luck!