modify source/(black/white.scss) and template/theme.scss
diff --git a/inst/reveal.js-3.3.0/css/theme/template/theme.scss b/inst/reveal.js-3.3.0/css/theme/template/theme.scss
index 9bb416a..101a567 100644
--- a/inst/reveal.js-3.3.0/css/theme/template/theme.scss
+++ b/inst/reveal.js-3.3.0/css/theme/template/theme.scss
@@ -207,7 +207,8 @@
 	text-align: right;
 }
 
-.reveal table tr:last-child td {
+.reveal table tbody tr:last-child th,
+.reveal table tbody tr:last-child td {
 	border-bottom: none;
 }