Showroom
noun
The room where you exhibit things in a row is a showroom. Maybe there are cars lined up, or boats, or tiny porcelain cats! Either way, they need a nice big showroom to show them off.
ちんれつしつ
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
その陳列室には、いったい何が並べられているのですか。
What the heck is on display in the showroom?