Joining Excel price lists, combining Excel spreadsheet mappings

I have experience merging data from different sources into Excel.

Examples:

1. Adding parsed information from the site to the price list in front of each product.
2. The output of prices for the same product from different price lists or sites.
3. Data connection of two or more price lists in one Exel file.
4. Analysis of the availability of products added to the database (on the site) and the output of this information in front of the product.
5. Analysis of the availability of photographs of the product on the disk and the output of this information in front of the item in the price list.
6. Combined more than 246 price lists and other Exel files. I did it for comparing prices, adding products to sites and analysis of expediency of adding them (product already added, no photo, etc. ), creation of generalized information about object from different sources.

This kwork includes:

1. One source, one data table.
2. Data is added to one single table file.
3. Up to 10 columns in the source.
4. Up to 20, 000 rows in the source and in the file where the data is added.
5. Linking tables by one attribute.