I understand what other browser specific code names such as -moz- and -webkit- are used, the former for mozilla and the later for chrome and safari, but what is -mso- exactly? It stands for Microsoft Office, but a web page is never brought up in that program, is it?
Your example code:
<style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style>
Looks like what would happen if someone copied and pasted text from a Microsoft Word Document into a WYSIWYG editor in a content management system.
MS Word puts in a ton of nasty code that is not needed. It's better to tell your content authors to paste in plain text instead of from MS Word.