I think there were issues if tables got too wide IIRC. Tables are a bit of a nightmare to deal with though. I would also personally prefer to not hide the borders for better readability, but I guess that's more of a preference and less of an issue.

For links, I have not been able to deduce a pattern. I usually test with the posts at !trendingcommunities@feddit.nl For a while I thought it was related to certain instances, but in today's post one of the links going to lemmy.ca opened in browser and another in Sync. Very puzzling.