There’s a table in the Introduction to Numbers lesson that is not suited to a phone. I haven’t run across any other examples, but the one is unusable. I think it probably has to be broken down into separate tables or or maybe there’s some responsive CSS black magic that can fix it. For now you may just need to let it stay as is. Also, I suspect you probably have some way to scan your content (or just know it well enough) to know where other instances of wide tables show up and seek out a more unified solution to how to deal with this issue.
One other thought: removing the “roman numerals” column and then separating out the multiplier and collective columns, which are very sparse, might be a good intermediate step.
This is definitely not a show-stopper.