Jayne, as far as I know the only filter which actually offers settings at the activity level is the Video Easy filter.
The others can simply be turned on and off at the activity level. If its just one page that you are worried about, then installing and setting up an alternate filter might be overkill. In this case you might just insert the video tags manually on the page with autoplay off. Maybe see here: http://www.w3schools.com/tags/att_video_autoplay.asp
If however you face this situation often, then the best way would be to install and set up the VideoEasy filter and leave it 'off but available.' Then go and turn it on just in the activities you need it (and turn off the multimedia plugins filter in the same activity.)