You can customize the border for any table row or any specific entry in the table.
For example, below code specifies a custom bottom border for all the entries in the third row of the table:
import mlreportgen.dom.*;
doc = Document('tables', 'docx');
t = Table(magic(5));
t.Style = {Border('solid'),RowSep('none'),ColSep('solid')};
% Specify a bottom border format
bottomBorder = Border;
bottomBorder.BottomColor = 'red';
bottomBorder.BottomStyle = 'solid';
% Add bottom border format to all the entries in the third row of the table
row3 = t.row(3);
row3Entries = row3.Children;
for i = 1:length(row3Entries)
row3Entries(i).Style = [row3Entries(i).Style {bottomBorder}];
end
append(doc,t);
close(doc);
rptview(doc);