I'm past the turning point, now, but felt in the dark about how to proceed at first, once the heavy 8 by 5 foot table had arrived and was awaiting set up. I spent a good part of a day developing more than ten possible plans on paper for how to arrange the furniture before moving anything. I have never done this before and what was interesting was how at first I thought there might be just a couple of ways, but as I persisted, more and more options became apparent. A good lesson for designing anything.
In the end, I still modified the plan I chose - ending up with kind of a 't' formed from my desk and sewing table and shifting the angle of that. Now comes alot of hauling up and down two flights of stairs and thinking about how best to organize my fabrics, books and supplies. Wherever I move something from, something else will have to be moved back, to replace it. The large table has a single flat storage shelf beneath it and I have some drawers that fit there, which is great.