Three short lines, and a whole small scene: bad weather outside, and people drifting in to sit together at a little table. The title, "Raw," sets the tone. It suggests the kind of cold, wet, unfinished weather that gets under your clothes, but it can also hint at feelings that are exposed and unpolished.
The speaker says "we," so they are one of the group, not an onlooker. The phrase "one by one" slows everything down. People arrive separately, not in a rush, and each one finds a place. Nothing dramatic happens, and that is the point. The weather pushes everyone indoors, and the shelter they find is small and ordinary.
The mood is quiet and close. There is a bit of chill in "wind and rain," but the "little table" feels snug by comparison. The poem seems to find comfort in simple company: when the world outside is harsh, a modest table and the people around it are enough.