<?php
// Add this code to your theme's functions.php file or a custom plugin

// Function to fetch data from a MySQL table and display it
function display_data_from_table() {
    global $wpdb;  // Access the WordPress database object
    
    // Define your custom table name (replace 'your_table_name' with your actual table)
    $table_name = $wpdb->prefix . 'your_table_name'; // Prefix adds wp_ or your custom prefix
    
    // Prepare SQL query to fetch data
    $results = $wpdb->get_results("SELECT * FROM $table_name", ARRAY_A);
    
    // Check if results are found
    if ($results) {
        // Start building the HTML table to display data
        $output = '<table>';
        $output .= '<thead><tr>';
        
        // Display table headers (adjust to match your table columns)
        foreach (array_keys($results[0]) as $column_name) {
            $output .= '<th>' . esc_html($column_name) . '</th>';
        }
        $output .= '</tr></thead><tbody>';
        
        // Loop through each row and display data
        foreach ($results as $row) {
            $output .= '<tr>';
            foreach ($row as $column_value) {
                $output .= '<td>' . esc_html($column_value) . '</td>';
            }
            $output .= '</tr>';
        }
        $output .= '</tbody></table>';
    } else {
        $output = '<p>No data found.</p>';
    }
    
    return $output;
}

// Register the shortcode to display the data
add_shortcode('display_data', 'display_data_from_table');

Sample Page