There are three icons at the top-right of each page; they are links 7, 8, and 9 in text view of the page. The first, which looks like a question mark (the alt-text is "accessibility features"), opens this page. The second icon has a small T next to a large T and this one reads "change text size" with a screen reader. This link increases the text size of the page in three increments and then back to the original size. The third icon has a T in reverse video and alt-text "change contrast." Activating this link changes to a white on black contrast mode - then, if activated again, back to usual contrast.
When you make these changes, and leave the site, and later come back, your settings will be saved thorough the marvel of cookies (see the privacy statement).
This site uses CSS for layout, not tables. I do not think that that is essential for accessibility at all. Recently I believe I have seen more questionable situations with reading order stemming from CSS based layouts than ever from table based layouts. And frankly, the CSS isn't easy. I tried to do one myself, and failed. More on this subject later!