I'm a very messy, spread out quilter. I went on my first quilt retreat last year and made a bunch of stuff to take. Here's the post:
Retreat items
I will say that the straddle bag worked really well, as a matter of fact, I continued to use it when I returned. I like having the items stored in it close, but not taking up any table real estate. We were permitted to bring a table to our retreat. The maximum dimensions were provided by the organizer. Rather than bring a TV tray or other folding tray, my girlfriend and I each brought one 12 gallon tote, similar to this:
https://www.amazon.com/Akro-Mils-12-...12+gallon+tote
They stacked, and together were the correct dimension for the permitted accessory table. I had my husband cut a piece of plywood for the top & put a cutting mat on that. My friend and I put it between us. I had a couple different brands of totes and some were less sturdy, so if you go this route, you need to make sure that the ones you choose will be sturdy enough to cut on. They held a ton of stuff and were very convenient, and we could slide it under the table when not in use.
Finally, i was glad I brought my acrylic extension table for my sewing machine. I could put small tools under it in an open top tray. easily visible, but yet out of the way.