I'm starting to create and add some autotext entries a template file and have noted that that when I go to insert that text later, the format is different?

All of my autotext are being created in the default 2010 word format of Calibri Body 11pt.

Yet some of them (not all) are later being inserted as Arial 9pt and in Bold?

Formatting is controlled by Styles especially when a paragraph mark is included in the entry. The styles may be defined differently in different documents and templates. If the style is already in use (and perhaps directly formatted to look different from the style settings) its definition will overrule the definition originally used in the AutoText entry. Automated Boilerplate Using Microsoft Word

For examples of styles altering appearance on inserted text, see the tutorial on the IncludeText field. It behaves similarly to AutoText. Especially look at the part on Styles.

For more about Styles, see Understanding Styles in Microsoft Word