See https://core.trac.wordpress.org/ticket/49089 and https://github.com/Automattic/Edit-Flow/issues/654

reproduction-trac-49089.php

<?php
/*
Plugin Name: Replicate core issue 49089
Plugin URI: https://core.trac.wordpress.org/ticket/49089
Description: Steps to replicate: (1) Visit wp-admin/edit.php, (2) Try to edit a post with "Quick Edit" to trigger the ajax action, (3) Check PHP error log (debug.log)
Author: htdat
Version: 0.1-dev
*/
add_action(
	'wp_ajax_inline-save',
	function () {
		new WP_List_Table(
			array(
				'plural'   => 'plural',
				'singular' => 'singular',
				'ajax'     => true,
				/**
				 * The PHP error does not happen if `screen` value is different from NULL or ``
				 * Removing the comment below will prevent the error from happening
				 */
				// 'screen' => 'anything',
			)
		);
	},
	/**
	 * Core calls this action with priority = 1, and since it's an AJAX request,
	 * the whole process is terminated early before the added action here can be reached out
	 *
	 * @see https://github.com/WordPress/wordpress-develop/blob/132984c20f4a539dddeeaf7f9f65716854a89b55/src/wp-admin/admin-ajax.php#L163-L165
	 */
	-1
);