That's interesting to me. You went in 93.8, they took of 0.5 (which is the normal "washback"or "rinseback" amount) - which also factors in your cuppa, yet you came off at 93.2 - 0.6 total down. That suggests you lost more fluid during the session(maybe sweating?).
Now I'm no expert, and there are others far more highly qualified than I to both explain this - and your BP - like Zach, kidneydoc, sluff and others, so I will just give you an opinion - for what little it's worth...
Are you still passing a lot of urine? I think maybe it was you that posted another thread recently about this? That could indicate they're just giving you dialysis and not taking off any more fluid apart from the washback (0.5l, or 500ml on the machine) - and that's fine I guess but in the long run you will probably need a dry weight established.
Basically the dry weight (sometimes also called the "Ideal Body Weight") is a guestimated target weight for someone where they're not carrying excess fluid in their system. As you'd know from reading IHD, excess fluid running around the body for a ESRD patient can be very serious - specially in larger amounts - as it affects the heart and lungs, pushes up BP (as the heart works harder under the strain) and so on - so the goal of dialysis is to take off as much fluid as possible without getting you too dry, which then causes a real *drop* in BP, a crash (fainting, etc) and/or cramps.
Seems to me "I don't know" isn't a very helpful answer. I might have said back "Do you know of anyone here who might be able to tell me?" or maybe just wait till I spoke with the neph.
You might want to ask them several questions next time:
a) why are they only taking 500ml off per session?
b) Will they establish a dry weight for you? If they have, what is it?
c) If you still have the BP issues late in your session can they explain it? If not I would speak to the neph about it.
In my humble experiene most of the time during HD the BP goes down. Sometimes it will shoot up for me, but as I said that seems to be an indication of too much fluid being taken. If I stop the UF (Ultrafiltration-the taking of fluid) things usually settle down.
Good luck with finding some answers!