The phrase "a modest room" is correct and usable in written English.
It can be used to describe a room that is simple, unpretentious, or not overly large or luxurious.
Example: "After a long day of travel, I was relieved to find a modest room waiting for me at the inn."
Alternatives: "a simple room" or "an unassuming room".
The trading floor is a modest room that was once the company's kitchen, before it downsized about a decade ago.
Holder put his desk in a modest room in the corner of the building, where the place of honor belongs to a portrait of Nicholas deB.
Tomma Abts's studio is a modest room, lit by a skylight, in an artist-run complex called Cubitt, in North London.
There was little time for much outside it, something evidenced by how he chose to live, renting a modest room in the Prestbury area of the town.
In the basement below, a modest room grandly called the Rose L. McCormick Memorial Auditorium, named after a beloved librarian and used as a meeting place for various groups.
Working in a modest room so crowded with recording gear that they spend much of their time toiling inches apart, Mr. Hermansen and Mr. Eriksen say they usually finish up by midnight or 1 a.m.
At a more modest room rate there's Palace Hotel, a four-star accommodation where the room costs almost half the price of Bürgenstock Hotel.
I feel like [Currents] was the last album I'll make in a really modest room in my house.
According to author Stephen Armstrong, this room had a "modest sitting room with a huge antique mirror, plush sofas and a CD player which didn't work.
He includes a photo of the modest room with a big yellow bed, straw chairs, paintings on the wall.
"I'm charging $10 for no other reason than that I need to buy paint". He includes a photo of the modest room with a big yellow bed, straw chairs, paintings on the wall.
