the "Try it online" feature: minor accessibility issues

First of all, thanks for this feature! It's really cool, as I've received a possibility to quickly experiment with different braille codes.

It looks like there're some accessibility issues, at least on Windows and NVDA (both Chrome and Firefox browsers have been tested). When in "table" selection list (combobox) and pressing up and down keys, the cursor jumps to the text input field. In other words, it's impossible to learn the list of tables in a normal way: after option is changed I need to press Shift+Tab to move back to the list, select another option, again press Shift+Tab to move back, etc.

Although users have the way to workaround it by switching NVDA to the brows mode and then pressing Enter to the list, it's really not obveously and isn't a normal use of case.

I'm quite bad in JS, moreover, you seem to have difficult focusing and scrolling rules, but I asume it's because of onChange listeners: when pressing arrow keys in the NVDA's edit mode, onchange event is coming immediately (the option is changed without any confirmation).

Start with the “Try it online” table combobox and inspect the JavaScript onchange, focus, and scrolling behavior described in the report. Reproduce the issue with NVDA on Windows in Chrome or Firefox; it is done when arrow-key selection lets users move through table options without focus jumping to the text input.