Display SQL table in WordPress

External to your WordPress installation, but in the same database?
Or external to your server?

If external to your server, this is not up to WordPress.
This is up to your remote server, remote database access, ports that may be open, or if there is API access availalbe.

If the table lives in the same database as your WordPress install, then you can output data using a plugin like WP Data Tables:
https://en-ca.ww.wp.xz.cn/plugins/wpdatatables/
https://wpdatatables.com/faqmd/create-mysql-query-uses-tables-multiple-databases/