It's important to know that Table Import only imports new records and does not update existing records. So, now, here's what you do. You need a file in a comma-delimited or tab-delimited format.
Enter a Definition ID and Description. These just need to describe what you're doing.
For the Source File Format, select one of the two options.
Select your file as the Source File.
The Destination Table should be VAT Country Code MSTR.
For fields present in your source file, double-click on them to select the source fields, one field at a time. For example, if Country Code is in your file, double-click the Country Code field and select the appropriate field from your file. Repeat this step for each field you have in your source file.
For fields not in your source file, you can hard-code a value by typing it in the Constant field and clicking Add. Make sure the field to which you are assigning the constant is selected first.
For fields you do not need, like, probably, the Note Index, leave it blank.
Lastly, once you map your data, back up your text file and remove the header row. If you leave the header row in the file, that row will be imported into GP. You don't want that junk.
Then click the Import button. A file with rjt will be created. Hopefully, it's blank. If it isn't, it's because you have duplicate values based on what GP allows in the destination table. You can use Notepad to open the file.
That's it!