It could be anything. Usually it's raw video going back to a station, sometimes it's a station being relayed to a different location. Most of them are very temporary though. And the symbol rates are only typical, they're set by the ground station, not by the satellite. I guess that Lyngsat lists the most frequent ones as guidelines for people who don't have blind-scanning receivers.
Those channels are unkown territory and generarlly true "FEED" channels. Meaning that they broadcast sporadically. ON and OFF without notice. They are not a consistant channel, but the transponder itself is reserved for their use. You never know when it will be active, usually. But the TP stays on line often with a color bar test pattern and audio test tone. But, sometimes the channel is just BLANK or black.
Lyngsat presents them as FEEDS with a grayed background because the content is variable and the broadcast times are unknown.
These are often the "most fun" channels as they are impromtu and raw (unedited) . This is the exciting part of FTA. This is often the stuff that you will not get via a subscription service. It can be very dull and then again it can be hilarious! Or shocking.
These "FEED" channels are what we want to scan with the blind scan option. They are fun! Could be a football game, a hockey game or pure news. The point is that it is the RAW feed prior to being edited at the studio. This means you get to view the bloopers live and first hand. It is a great deal of fun if you want to wait for the good pieces.
EDIT: Some are encrypted, some are not. The content on one channel may be encrypted one day and later that afternoon it may be ITC. All depends. It is a grab bag like going to a garage sale.