Unfortunately you can’t use the Export-CSV cmdlet to export a custom HashTable to a CSV file (Not directly) I found you could convert it to a PSObject which can be directly piped to Export-CSV.

$OutputTable = $MyHashTable.getEnumerator() | foreach{
    New-Object PSObject -Property ([ordered]@{Computer = $_.Name;Time = $_.Value})
}

$OutputTable | Export-CSV test.csv -NoTypeInformation