Option Explicit
Sub CreateTable()
    Dim tbl1 As Range
    Dim tbl2 As Range
    Dim tbl3 As Range
    Dim c As Range
    Dim cRow As Variant
    Application.ScreenUpdating = False
    With ActiveSheet
        Set tbl1 = .Range(.[E3], Cells(.Rows.Count, "E").End(xlUp)).Offset(, - 1 ).Resize(,  3 )
        Set tbl2 = .Range(.[B3], Cells(.Rows.Count, "B").End(xlUp)).Offset(, - 1 ).Resize(,  3 )
        Set tbl3 = tbl1.Offset(,  3 )
        'Copy existing table
        tbl1.Copy .[G3]
        For Each c In tbl2.Columns( 1 ).Cells
            cRow = Application.Match(c, tbl1.Columns( 1 ).Cells,  0 )
            If IsError(cRow) Then
                'Copy missing data
                c.Resize(,  3 ).Copy .Cells(.Cells(.Rows.Count, "H").End(xlUp).Row +  1 , "G")
            Else
                'Update the existing data
                tbl3(cRow,  2 ) = c.Offset(,  1 )
                tbl3(cRow,  3 ) = c.Offset(,  2 )
            End If
        Next c
    End With
End Sub