In just four lines, the speaker imagines two very different positions. First, he pictures himself among the dead and feels he would be "a sorry stranger," out of place and a little pitiful, someone who doesn't belong even in death. The tone is wry rather than frightened, as if he's admitting an awkwardness more than a terror.
Then the poem turns. He says he thinks about providence, the idea that a larger plan guides events, but he does so "from the bottom of a clock." That odd image sets grand ideas against something small and mechanical. A clock measures time in tiny ticks, and the speaker seems to sit at its lowest point, looking up at the workings. The title, "Small time," fits this: he sees himself as a minor figure in a vast scheme.
The mood is quiet, humble, and slightly humorous. Death and fate are big subjects, but the speaker approaches them from a modest, almost cramped vantage point, and that mix of seriousness and playfulness gives the poem its charm.