Translation:Nobody wants our table with two legs.
Numbers two "dva, oba, tři, čtyři" use special declension patterns you must remember. "Dva" and "oba" use the old dual forms, so instrumental "dvěma, oběma". Dual used to be many hundreds years ago a separate grammatical number along singular and plural and was used for two objects. Number three "tři" does not use the dual declension and has instrumental "třemi".
You can check wiktionary for the declension https://en.m.wiktionary.org/wiki/t%C5%99i
However, Common Czech, the most common dialect spoken in common speech, does use "třema" and "čtyřma". This is considered incorrect literary Czech.
I see. I used the standard Czech name today at a different question, I did some search and it appears to be more widespread although I did.not invent the term.and some do use it.
But there are more vernacular Czech dialects and Common Czech is just one of them, although it has the most speakers.