call_user_func_array() expects parameter 1 to be a valid callback

wp_slider_info_page is method of a class.

Function in class has to be set like this:

array( $this, 'wp_slider_info_page' )

only then WP knows that it is part of current class.

Replace

add_menu_page('wp Slider', 'wp Slider', 'administrator', 'slider-info', 'wp_slider_info_page', 'dashicons-format-video');

with

add_menu_page('wp Slider', 'wp Slider', 'administrator', 'slider-info', array( $this, 'wp_slider_info_page' ), 'dashicons-format-video');