Adding 1em spacing above and below tables in rendered html.

IPython/html/static/notebook/less/renderedhtml.less

@@ -75,6 +75,14
         margin-top: 1em;
     }
 
+    p + table {
+        margin-top: 1em;
+    }
+
+    table + p {
+        margin-top: 1em;
+    }
+
     img {
         display: block;
         margin-left: auto;

IPython/html/static/style/ipython.min.css

@@ -176,6 +176,8 div.quickhelp{float:left;width:50%;}
 .rendered_html th{font-weight:bold;}
 .rendered_html p{text-align:justify;}
 .rendered_html p+p{margin-top:1em;}
+.rendered_html p+table{margin-top:1em;}
+.rendered_html table+p{margin-top:1em;}
 .rendered_html img{display:block;margin-left:auto;margin-right:auto;}
 .rendered_html .MathJax_Display{text-align:center !important;}
 span#save_widget{padding:0px 5px;margin-top:12px;}

IPython/html/static/style/style.min.css

@@ -1557,6 +1557,8 div.quickhelp{float:left;width:50%;}
 .rendered_html th{font-weight:bold;}
 .rendered_html p{text-align:justify;}
 .rendered_html p+p{margin-top:1em;}
+.rendered_html p+table{margin-top:1em;}
+.rendered_html table+p{margin-top:1em;}
 .rendered_html img{display:block;margin-left:auto;margin-right:auto;}
 .rendered_html .MathJax_Display{text-align:center !important;}
 span#save_widget{padding:0px 5px;margin-top:12px;}