Looks like you've discovered many of the issues that I experienced many years ago
At that time, I used a work-round as follows
Code:
Private Sub cmdTable_Click()
'Next line not supported
'Me.WBrowser.Object.Document.execCommand "InsertTable", True, Null
'This inserts a table at end of existing code!
Dim msg, Style, Title, Response, MyString
msg = "This inserts a 2x2 table at the end of the HTML message. " & vbNewLine & _
"This can be moved later by dragging & dropping" & vbNewLine & vbNewLine & _
"Are you sure you want to create a table? "
Style = vbYesNo + vbInformation + vbDefaultButton2 ' Define buttons.
Title = "WARNING" ' Define title.
Response = MsgBox(msg, Style, Title)
'If user chooses No, return to selection box.
If Response = vbNo Then Exit Sub
'If user chooses Yes, insert table
'first copy all existing HTML code to clipboard
Me.WBrowser.Object.Document.execCommand "SelectAll", False, Null
Me.WBrowser.Object.Document.execCommand "Copy", False, True
'Add the 2x2 table
With Me.WBrowser.Document
.writeln "<table>"
.writeln "<tr><td>Table Cell A1</td>"
.writeln "<td>Table Cell B1</td>"
.writeln "</tr>"
.writeln "<tr><td>Table Cell A2</td>"
.writeln "<td>Table Cell B2</td>"
.writeln "</tr>"
.writeln "</table>"
End With
'paste the original code from the clipboard
Me.WBrowser.Object.Document.execCommand "Paste", False, True
End Sub
Hopefully it can be improved upon . . .