Wow, this is confusing. It took three posts to realize Aaron's AC server is in the cloud.

I am willing to bet it has nothing to do with AC at all. It certainly doesn't have anything to do with SQL especially if SQL 12. The queries really shouldn't have an issue with 1.7GBs. The key is to have a standard or non-express SQL. Then you get rid of the RAM limitation. Each query will then be cached as a "page" in the SQL memory.
It would be helpful to have more information on your setup. Is this Indy's hosted AC? If not, how are you connected to the cloud? I can't be certain due to the setup, but when I load a chart, I am loading all of that patient's chart into RAM. So moving between tabs is nearly instantaneous. If you are accessing AC via the Internet, each tab would be another page to load, correct? When you compare your setup with Boondoc's you have two obstacles he doesn't have. A partial wireless setup and the Internet.
Run a speedtest at
http://www.dslreports.com/speedtest or use your ISP's version if they have it. Time-Warner has their own. Compare the download speed (I don't think upload speed will matter nearly as much until you load and save data), and report them here. Compare the speeds with Gb speed on a wired LAN.
I completely agree with Boondoc. When using AC all day to see patients, I would think that everyone would want the fastest and most secure setup. That would be hard wired to a server at your location.
When you load a web page, it is cached on your computer. The next time you go to that page, it will load extremely fast. This may be what is happening with your tabs being faster the second time around.