Powerpoint doesn’t let me adjust the height of a cell in a table

The length of the row is based on the font size accordingly. Change the font size, and you will be able to adjust the height.

Try something like this. I've made a few mods so that it replaces any instance of the text @COL1@ on the slide with values from the worksheet. Untested aircode, mind you.

Sub CreateSlides()
'Open the Excel workbook. Change the filename here.
Dim OWB As New Excel.Workbook
Set OWB = Excel.Application.Workbooks.Open("C:\list.xlsx")
'Grab the first Worksheet in the Workbook
Dim WS As Excel.Worksheet
Dim sCurrentText As String
Dim oSl As Slide
Dim oSh As Shape
Set WS = OWB.Worksheets(1)
Dim i As Long
'Loop through each used row in Column A
For i = 1 To WS.Range("A65536").End(xlUp).Row
    'Copy the first slide and paste at the end of the presentation
    ActivePresentation.Slides(1).Copy
    Set oSl = ActivePresentation.Slides.Paste(ActivePresentation.Slides.Count + 1)
    sCurrentText = WS.Cells(i, 1).Value

    ' find each shape with "@COL1@" in text, replace it with value from worksheet
    For Each oSh In oSl.Shapes
      ' Make sure the shape can hold text and if is, that it IS holding text
      If oSh.HasTextFrame Then
        If oSh.TextFrame.HasText Then
          ' it's got text, do the replace
          With oSh.TextFrame.TextRange
            .Replace "@COL1@", sCurrentText
          End With
        End If
      End If
    Next
Next
End Sub