merchandise department 是具体什么部门?

商业化部门，可以这么理解吧。
The merchandising deparment 为公司选择可能盈利的产品并参与定价决策。

“The merchandising department may have to deal with some of the costing and pricing. The merchandiser aids creating a product line that should create a profit for the company, by executing the correct costing and pricing for these particular products. They have to lead their customer forward in creating new products. This may be taking risks for the company that may include getting rid of products that do not sell, of products that have become ‘stale’ (killing the ‘dogs’). The merchandiser has lots of responsibilities from guiding product development, market and product analysis to sampling and following up on shipments. ”