I took the initiative to contact Sue Wilton, who is the manager of the restaurant "El Plato".

took 是动词 take 的过去式，take 的基本意思是"拿、采取"。 the 是定冠词，表示特指某个人或事物。 initiative 是名词，来自形容词 initial（最初的），加上后缀 -ative 构成，表示"主动性、首创精神"。take the initiative 是一个固定搭配，意思是"采取主动、主动做某事"。