This is the 1909th most frequent Japanese word.
表面
"Surface" or "exterior."
Here, '表面' refers to the exterior or topmost layer of the table.
このテーブルの表面は磨りガラスでできています。
The surface of this table is made of frosted glass.
In this sentence, '表面' denotes the outermost layer for temperature measurement.
物体の表面温度を測定しました。
We measured the surface temperature of the object.
'表面上' here is used metaphorically to mean superficial or outward appearance.