An example of how to alter translations using the gettext_with_context filter.

functions.php

<?php //Please do not include the opening PHP tag if you already have one.

function tw_ee_gettext_with_context( $translated, $text, $context, $domain ) {
    if ( 'event_espresso' == $domain ) {
        if ( '(For %1$s)' == $text && '(For Event Name)' == $context ) {
            $translated = '(%1$s)';  //Remove the 'For'
        }
    }

    return $translated;
}
add_filter( 'gettext_with_context', 'tw_ee_gettext_with_context', 10, 4 );

Reference:
https://eventespresso.com/topic/event-name-in-invoice-an-registration/
https://eventespresso.com/topic/line_item_description-edit-the-text/#post-229358