Use the ExpandProperty parameter on the Select-Object cmdlet, that way you only get the value.
@{N="vmk1 IP Address";E={Get-VMHostNetworkAdapter -vmhost $_ -Name vmk1 | select -ExpandProperty "IP"}}
Use the ExpandProperty parameter on the Select-Object cmdlet, that way you only get the value.
@{N="vmk1 IP Address";E={Get-VMHostNetworkAdapter -vmhost $_ -Name vmk1 | select -ExpandProperty "IP"}}