util.human.io: Consider separator when calculating remaining width

util/human/io.lua

@@ -110,6 +110,9 @@ local function new_table(col_specs, max_width)
 			width = math.max(tonumber(width), title and (#title+1) or 0);
 			widths[i] = width;
 			free_width = free_width - width;
+			if i > 1 then
+				free_width = free_width - #separator;
+			end
 		end
 	end
 	-- Calculate width of %-based columns