Yes, you can convert an ASC file to a CSV file using Microsoft Excel. The size of the file does make a difference as it may take longer to convert a larger file. However, it is still possible to convert a large file as long as you have enough storage space and processing power on your computer.

To convert an ASC file to a CSV file using Microsoft Excel, follow these steps:

1. Open Microsoft Excel and click on the "Data" tab.
2. Click on "From Text/CSV" in the "Get & Transform Data" section.
3. Navigate to the location of the ASC file and select it.
4. Click on "Import" and select "Delimited" as the file type.
5. Choose the delimiter used in the ASC file (e.g. comma, tab, semicolon) and click "Next".
6. Select the columns that you want to import and choose the data format for each column (e.g. text, number, date).
7. Click "Finish" to import the data into Excel.
8. Click on "File" and select "Save As".
9. Choose "CSV (Comma delimited)" as the file type and save the file.

As for your computer's specifications, it may take longer to convert a large file with only 512 MB of RAM and a Pt M 1.73 Ghz processor. You may experience slower performance or even crashes if your computer is not able to handle the task. It is recommended to have at least 4 GB of RAM and a faster processor for handling large files.