"The vegetable on the table is the cauliflower."
Translation:Leguma de pe masă este conopida.
When talking about an object situated somewhere, you would use a preposition that sort of has the meaning of "from". Probably not the clearest explanation, so here's some more examples:
The clothes in the closet are expensive. - Hainele din (not în) dulap sunt scumpe.
The chair next to the table is red. - Scaunul de lângă masă e roșu.
The books on the second shelf are old. - Cărțile de pe al doilea raft sunt vechi.
The bathroom downstairs is enormous. - Baia de jos
* e enormă.
The monsters under the bed eat children. - Monștrii de sub pat mănâncă copii.
(At least in the last example, you can insert "from" in the English sentence).
* There isn't a word for "downstairs" in Romanian.