Tools > Plugins > Snippets

With the Snippets plugin open (default on the left).
Expand the “HTML” folder: You’ll see, “Convert Selection to Entities”

i.e. Ctrl+Shift+5

Also, in the HelpFile

EmEditor Home – EmEditor Help – Features

For Web Designers

EmEditor is an ideal tool for editing HTML, PHP, JSP and XML files. By specifying an Internet browser as an external tool, you can preview HTML files while editing them. HTML and scripting language keywords are highlighted according to HTML or independent scripting language configurations, which makes finding spelling errors and typos easy. Unicode characters are automatically converted to the HTML/XML character reference ( &H10070; ) or named entity reference ( © ). EmEditor can use a code page specified at the tag “charset=” line, and furthermore, you can use plug-ins to insert various tags or verify XML documents with an XML Parser.