How to parse HTML table with Powershell Core 7?

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PowerShell (Core), as of 7.3.4, does not come with a built-in HTML parser – and this may never change.

You must rely on a third-party solution, such as the PowerHTML module that wraps the HTML Agility Pack.

The object model works differently than the Internet Explorer-based one available in Windows PowerShell; it is similar to the XML DOM provided by the standard System.Xml.XmlDocument type ([xml])[1]; see the documentation and the sample code below.

# Install the module on demand
If (-not (Get-Module -ErrorAction Ignore -ListAvailable PowerHTML)) {
  Write-Verbose "Installing PowerHTML module for the current user..."
  Install-Module PowerHTML -ErrorAction Stop
}
Import-Module -ErrorAction Stop PowerHTML

# Create a sample HTML file with a table with 2 columns.
Get-Item $HOME | Select-Object Name, Mode | ConvertTo-Html > sample.html

# Parse the HTML file into an HTML DOM.
$htmlDom = ConvertFrom-Html -Path sample.html

# Find a specific table by its column names, using an XPath
# query to iterate over all tables.
$table = $htmlDom.SelectNodes('//table') | Where-Object {
  $headerRow = $_.Element('tr') # or $tbl.Elements('tr')[0]
  # Filter by column names
  $headerRow.ChildNodes[0].InnerText -eq 'Name' -and 
    $headerRow.ChildNodes[1].InnerText -eq 'Mode'
}

# Print the table's HTML text.
$table.InnerHtml

# Extract the first data row's first column value.
# Note: @(...) is required around .Elements() for indexing to work.
@($table.Elements('tr'))[1].ChildNodes[0].InnerText

A Windows-only alternative is to use the HTMLFile COM object, as shown in this answer, and as used in your own attempt – I’m unclear on why it didn’t work in your specific case.

[1] Notably with respect to supporting XPath queries via the .SelectSingleNode() and .SelectNodes() methods, exposing child nodes via a .ChildNodes collection, and providing .InnerHtml / .OuterHtml / .InnerText properties. Instead of an indexer that supports child element names, methods .Element(<name>) and .Elements(<name>) are provided.

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