[wpml-string context="my-domain" name="block-number-1"]
<p>Content coming from block line 1</p>
<p>Content coming from block line 2</p>
<p>Content coming from block line 3</p>
[/wpml-string]
After adding this content block to your template, you can visit the front-end page that uses this template, so that this can be picked up by the WPML string translation feature.
It will then be available to be translated into other languages, through WP Admin -> WPML -> String Translations.