Custom template files for multiple blocks provided by a custom module?
If you want to use a different template file for your blocks, by default Drupal uses the following template files.


block--epic-module.tpl.php for all the blocks implemented by the module you are showing
block--epic-module--awesome-block.tpl.php and block--epic-module--epic-block.tpl.php for the blocks implemented by that code


Keep in mind that each underscore in the module name or in the block name (i.e. what the documentation calls delta) is replaced with a hyphen.

Reference


template_preprocess_block()