Do your plastic-model building at home, please. The smell of lacquer is filling up the whole room, y'know?
Literal
Plastic-model making [topic-は] home [at-で] do-please [よ]. Lacquer-liquid [gen-の] smell, is-filling-up [isn't-it-じゃないですか].
プラモ is a casual contraction of プラモデル ('plastic model'). ラッカー液 ('lacquer fluid') is the paint/thinner used in model-making. 充満する ('to fill up, to saturate') is a compound verb emphasizing full occupation of a space. The sentence-final じゃないですか is the rhetorical tag 'isn't it the case that...?,' seeking acknowledgment rather than answer. Polite but complaining — a characteristic mix when dealing with a hobbyist housemate.