XHTML Errors in Template-Confused…

I’m trying to make sure that my page is XHTML compatible, but I’m getting some wierd errors that I don’t understand…
They read like so…
[code] # Line 261, column 27: document type does not allow element "table" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
<h6><table id="wp-calendar">
^
# Line 318, column 78: document type does not allow element "form" here; missing one of "object", "applet", "map", "iframe", "ins", "del" start-tag
...action="/blog/index.php" method="get"><input type="text" name="s" size="14" v [/code]
You can view the validation at:
https://validator.w3.org/check?uri=http%3A%2F%2Fzanthria.com%2Fblog%2Findex.php
Any help?