Code works in html test bed, but doesn't in my wordpress template

Can a wordpress.org template override an html code? And if so, how do I get around it without changing the template if I’m on a non-admin account?

For example, if you run this through an html test bed, it gives me this a nice little table:

[Code moderated as per the Forum Rules. Please use the pastebin]

But when I publish this in wordpress, the table border doesn’t show up nor the 8 size font of the date. Any nuggets of wisdom you can provide? I have a feeling that the template is preventing me from seeing these changes, and if so, how can I get around that if I can’t change the template? Thanks so much in advance!