"Мы едим этот бутерброд."
Перевод:We eat the sandwich.
Native english speaker here brushing up on my russian. While grammatically correct, the suggestion with this sentence is that multiple people are sharing a sandwich, which seems odd. I would find "We eat sandwiches" more normal use of language (but not what the russian phrase was here of course), vs "We share the sandwich" if indeed multiple people are sharing one sandwich (also not a correct translation of the russian). So in general I don't think this sentence teaches very good english.
I agree, but we didn't create English sentences, they were given to us. This one is at least grammatically correct, there are many others which are not. We usually delete them, but it is not always possible, because there is a limited number of sentences in the course. Check this https://www.duolingo.com/comment/1457433