As I was going through Community Forun question I found this question and I wanted to try myself in my trial instance.
follow below approach which i have tried in my trial and it is working as expected.
1. Create CSV file with only four column
2. Save this file on your local machine. Now navigate to Settings->Data Management->Import Data->Browse csv File->Next->next->Select Notes entity in dropdown
3. Click Next and map Account lookup to set based on full name
4. Now map Owner lookup based on full name
4. click next ->next->submit->wait for the import to complete
5. check account record and see below image all 3 records notes are imported successfully
Hope this helps!