Your code segment works here, and the code is processed sequentially, though I would prefer that you named the table, and you do need to add End With
Is there some reason why you think there may be a holdup?
There would be an error if the macro was run again (or a separate table was added) and there was no separation between the tables.

    Dim myRange As Range
    Dim oTable As Table
        ActiveDocument.Range.InsertParagraphAfter
        Set myRange = ActiveDocument.Range
        myRange.Collapse direction:=wdCollapseEnd
    
        ' Create and populate the first table on the form
        Set oTable = ActiveDocument.Tables.Add(Range:=myRange, numRows:=2, numColumns:=2)
    
        With oTable
            .Columns(1).PreferredWidth = CentimetersToPoints(4.5)
            .Columns(1).Shading.BackgroundPatternColor = RGB(192, 192, 192)
            .Columns(1).Cells(1).Range.ParagraphFormat.Alignment = wdAlignParagraphRight
            .Columns(1).Cells(1).Range.Bold = True
            .Columns(1).Cells(1).Range.Text = "Assignment Title:"
            .Columns(1).Cells(2).Range.ParagraphFormat.Alignment = wdAlignParagraphRight
            .Columns(1).Cells(2).Range.Bold = True
            .Columns(1).Cells(2).Range.Text = "Assessor:"
            .Columns(2).PreferredWidth = CentimetersToPoints(11.5)
        End With