csvtodt.csv

$csvfile = "C:\perf\bigperf.csv"
$csvfile = "C:\perf\tab.csv"
$csvdelimiter = "`t" # `t for tab
$firstrowcolumnnames = $false

Write-Output "Script started..."
[void][Reflection.Assembly]::LoadWithPartialName("Microsoft.VisualBasic")
$elapsed = [System.Diagnostics.Stopwatch]::StartNew() 

$csv = New-Object Microsoft.VisualBasic.FileIO.TextFieldParser($csvfile)
$csv.TextFieldType = "Delimited"
$csv.SetDelimiters($csvdelimiter)
$csv.CommentTokens =  "#"

$datatable = New-Object System.Data.DataTable
Write-Warning "Filling datatable"
$columns = (Get-Content $csvfile -First 1).Split($csvdelimiter)

foreach ($column in $columns) { 
	if ($firstrowcolumnnames -eq $true) {
		[void]$datatable.Columns.Add($column)
	} else { [void]$datatable.Columns.Add()} 
} 

while (!$csv.EndOfData) {$null = $datatable.Rows.Add($csv.ReadFields())}

if ($firstrowcolumnnames -eq $true) { $datatable.Rows.Remove($datatable.Rows.Item(0)) }

$totaltime = [math]::Round($elapsed.Elapsed.TotalSeconds,2)
Write-Host "Total Elapsed Time: $totaltime seconds. $($datatable.rows.count) rows added." -ForegroundColor Green