lot：是表示 “量” 的名词， “（一）套；（一）组”。

two lots of：两套；两组。

two lots of tests：两套/两组测试。= two sets of tests

would 是“推测用法”，表示“有可能”。属于婉转，留有余地。含义是“一套测试就能做到，为何要有两套呢？” （一套测试估计能做到，但拿不准，才用 would 推测）

句子语序属于倒装性质，类似：asked Tom.  正常语序为：

So, businesses on both sides of the Atlantic ask, why have two lots of tests where one would do?

ask 后没有引号，属于“自由间接引语”。