Explode Array from Repeatable Custom Field

This is more of a PHP question than a WordPress question.

Try to replace

$temp = explode( "|", $am );

with

$temp = explode( "|", $am[0] );

since $am is an array.

You should also consider using isset() to check if the array items exists.

Here is one idea:

<?php

$affman = get_post_meta( $post->ID, 'affiliatemanager', FALSE ); 

if ( is_array( $affman ) ){

    $li = '';
    foreach($affman as $am) {
        $temp = array();

        if( isset( $am[0] ) )
            $temp = explode( '|', $am[0] );

        if( count( $temp ) === 5 ){
            $am_name  = $temp[0];
            $am_email = $temp[1];
            $am_aim   = $temp[2];
            $am_phone = $temp[3];
            $am_skype = $temp[4];
            $li .= sprintf( '<li>Name: %s | Email: %s | AIM: %s | Phone: %s | Skype: %s </li>', 
                            $am_name, 
                            $am_email, 
                            $am_aim, 
                            $am_phone, 
                            $am_skype 
                        ); 
        }
    }
    printf( '<ul>%s</ul>', $li );
}

?>