Excel 2010: Can you merge multiple columns, but keep all data?

I have made a large excel sheet with over 1000 items/rows. There are currently about 70 fields (with 70 different columns) that are all different. But I want to reduce that number. I want to merge many of them, but keep the data, and separate them by commas or something. But the data may be different in these columns. For example, I have 10 columns (Brass, Aluminum, Glass, etc). I want to make those 10 columns one, and I want it to list the different material types in one column. And some items may have multiple material types, so I need them separated by a comma or space.
I attached 2 pictures of an example of what I want.

Data sheet example part 1.JPG


Data sheet example part 2.JPG

Could someone please tell me the process, point me to a page, or a video tutorial?