I'm running a hotspot service at a resort but need to add netflix and such to the walled garden whitelist so that the devices can run without having to login.  I've looked around but can't seem to find what to add to the whitelist,  it seems that it could be several hundred entries of AWS servers.  Is there an easier way?

you should add address in walled garden that you want open them

In theory you can add wildcards in /ip hotspot walled-garden  eg *.netflix.com or *netflix*.  You would need to add other domains netflix uses too.  There are known problems with this and HTTPS though.  This thread is for Facebook but the principle is the same and it discusses some of the problems / options:  http://forum.mikrotik.com/viewtopic.php?t=72303