Over 50% of traffic for my amazon aff site is mobile, but my lovingly-crafted tables get all buggered up, showing as a vertical list rather than a horizontal comparison - totally defeating the object of the table.

I know from searches it's not an uncommon problem and as far as i can tell the best solution is scrollable tables.

Is there anything better than that? I've tried all major WP table plugins plus a few obscure ones.

If you are using table plugins, I am replying on the presumption that this is for on page content and not a woocommerce product compare solution. The only way I have got around this is;

a) as you say scrollable tables which are not the best (tablepress does have a plugin for this I can drag it out if you need) or
b) using wp bakery and table press and physically seperating the tables on mobile to have more than one. I hid the main table and show the multiple tables on mobile under column settings.

Here is an example (it will show the break if you resize the browser)
https://www.thebakewelltart.com/more-information/cake-portion-cutting-guide/

Thanks Leona, very helpful.