I sounds like you have gotten a lot of good suggestions...any one of them would work, however I sure hate to hear you ladies talk about losing height. I am one of the vertically challenged - 5' even - I haven't really lost any height yet, but I'm sure I will, just don't like to think about it. At 73 yo I have learned to deny a lot of things.

This concept is good, but an actual sleeper, or railroad tie, as they are known in parts of the US, would not be safe to use in the house because they are treated lumber. Arsenic is one of the preservatives that might leach out. Creosote, another one, is considered carcinogenic.

At a resale shop you may be able to find a nice size platform that was designed for stair stepping exercise in the 1980's, and that would be safer than a small step stool. You'd always have to be mindful of your feet, though.

if you cut the legs down you may still be able to easily move the tables by putting tennis balls on them. When my hubby was using a walker he put tennis balls on the legs without wheels and it made using the walker so much easier. Just cut a hole in the ball big enough for the legs.

Well I am lucky that mine is wooden, so I can cut it down. However I have a sewing chair that my legs were dangling from since I'm only 5' too. I went to a caster store and they sold me better casters and cut down my chair legs (also wooden) to attach the new casters. Love it, love it. I think I'll take the table in now and they can put better casters on it and cut it down too. Thanks for posting the question.

Try a piece of plywood, the whole side of the table size,including walking area. Added a rug scrap on top. Inexpensive.
crochet a rug if want out of narrow strips.

If you prefer having the rollers on, then take them off, take the amount off to include the height of the rollers than attach them back on. You really shouldn't be sitting when cutting with a rotary blade unless you are ancient and old like me! :)