The columns are defined in %ages which appears to be read according the the “inspect element”
The table is set at 950 px which is the size of the container.
Why then should the table expand so much so that it goes way off the page?
Take note of the commas, each comma separates a selector.
.edsfor1841 td, tr, th {}
So .edsfor1841 td selects only td’s in the class edsfor1841 then after the comma tr selects any tr and th selects any th because they are not paired with any class, id or other element.
In that, the first selector is the same, but the second selector selects any th inside a tr, which is effectively any th again, as in a valid table they will always be in a tr.