Welcome in!
That looks like a fun machine! Looks like the video capture card, the TV tuner, and the presentation system port, which created a mirror of the built-in display for use with a projector, since these were option used in education.
This is often already known, but just in case: The talking points about the 5200/6200 aren't true and these perform "fine", if a little slow in accordance to the fact that they were consumer machines. The 5300/6300 have updated CPUs (and, critically, more L1 cache) and are reasonably faster than the 5200/6200. The PowerBook 1400/2300/5300 which also use this architecture typically have the upgraded L1 cache, although not all of the PowerBooks have any L2 cache, and all 5200/6200/5300/6300 have 256k L2 cache. (6360/6400 and 4400/6500, that cache was optional, but L2 became standard in the L3 and the main differentiator was "how much" with consumer Macs having 256-512k and pro Macs having 512k-1M.)
Curious to see how well the capture works. It should work great as pass-through but even higher end Macs from this and slightly later eras aren't really "good" at capturing video, the way midrange software tended to do it was to use serial controlled VCRs and capture until a frame dropped, then stop, rewind, and continue from that point. (DV software does this too, with firewire devices.) You can turn down the size and frame rate or just do smaller segments by hand, as well.