Dim i As Integer

'First, Loop through each table; you may perfer to pick a table explicitly
For i = 1 To Word.ActiveDocument.Tables.Count
    'Create some variables to hold row and column values
    Dim x, y As Integer

    'Loop through the rows in the table
    For x = 1 To [WordInstance].Tables(i).Rows.Count
        'Loop through the coloumns for each row
        For y = 1 To [WordInstance].Tables(i).Columns.Count
               'Try to read the value of cell X,Y
               Try
                   Dim CellValue as String
                   CellValue = [WordInstance].Tables(i).Cell(x, y).Range.Text)
               Catch ex As Exception
                   'If we get an error, there is no cell at X,Y because Y is merged with the cell
                   'above, so increase Y by 1
                   y+=1
               End Try
        Next
    Next
Next