In its most basic form, that’s quite simple:
Import-Csv -Path yourCsvFile.csv | ConvertTo-Html | Out-File -FilePath yourNewHtmlFile.html
This example just creates a fairly bland HTML table. There are lots of little things you can do to tweak the look of the resulting HTML (including CSS code, etc.) If you click the Newsletter link along the top of this site, you’ll find a link to a free eBook called “Creating HTML Reports in PowerShell.”