How to create new table in magento 2.3

First of all, create db_schema.xml file inside /Vendor/Module/etc and write the following code :

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<schema xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Setup/Declaration/Schema/etc/schema.xsd">
    <table name="table_name" resource="default" engine="innodb" comment="comment_here">
        <column xsi:type="smallint" name="column_name" padding="6" unsigned="false" nullable="false" identity="true" comment="ID"/>
        <column xsi:type="varchar" name="column_name" nullable="false" length="25" comment="Name"/>
        <column xsi:type="varchar" name="column_name" nullable="false" length="25" comment="Email"/>
        <column xsi:type="varchar" name="column_name" nullable="false" length="255" comment="Descrition"/>
        <constraint xsi:type="primary" referenceId="PRIMARY">
            <column name="id"/>
        </constraint>
    </table>
</schema>

• <table> .. </table> = “Use for create and set table name”
• <column> .. </column> = “Use for create and set column of the table”
• <constraint> .. </constraint> = “Use for set constraint as like
  primary key, foreign key, unique key etc.”

Before running the upgrade command you need to add your schema to db_whitelist_schema.json file by running the following command :

php bin/magento setup:db-declaration:generate-whitelist --module-name=vendor_module

Now, there are db_whitelist_schema.json file will be create in /vendor/module/etc folder.