The word " counter" here just refers to a long, tall desk.

这里的“柜台”一词指的是一张又长又高的桌子。

When you're at the test center, there will be a word counter on the screen as you write. Please use it.

当你在考场的时候，当你写的时候，屏幕上会有一个单词计数器。请使用它。

Finally, you'll have space to write your own response and you'll have cut-paste undo and redo controls, and a word counter will be displayed as you type your answer.

最后，你将有空间编写自己的回答，还有剪切、粘贴、撤消和重做按钮，并且在你键入答案时将显示一个单词计数器。