Add vertical space around tables

Change-Id: Ic682942768d9a06bf4e76898959ba5be93bab021
diff --git a/inst/rmarkdown/templates/posterdown_ids/resources/template.html b/inst/rmarkdown/templates/posterdown_ids/resources/template.html
index be4c507..1b8572b 100644
--- a/inst/rmarkdown/templates/posterdown_ids/resources/template.html
+++ b/inst/rmarkdown/templates/posterdown_ids/resources/template.html
@@ -344,6 +344,8 @@
 table {
 font-size: 25pt;
 margin: auto;
+margin-top: 6mm;
+margin-bottom: 10mm;
 border-top: 3px solid #666;
 border-bottom: 3px solid #666;
 }