Welcome!
WordPress already have a table for users. Also, there is another table named usermeta that will allow you to save extra information for users.
There are some functions that allow developers to get information from user and usermeta tables without using custom database queries.
Solution: As mentioned in the question, users should see only their own data. So we can consider that the user is logged in to the site.
In order to get the current user, use the wp_get_current_user functions.
The rest of the things will be done using user meta. Update a user meta based on data and it will be saved on the usermeta table. And get it whenever you want to show it.
$current_user = wp_get_current_user(); // Getting current user logged in.
$user_id = $current_user->ID; // Get user ID to use in meta function.
// Custom html markups
// Show user name using first name and last name.
echo 'User name: ' . $current_user->user_firstname . ' ' . $current_user->user_lastname . '<br>';
// Show extra information.
echo get_user_meta( $user_id, 'prefix_user_exercise', true ) . '<br>';
And consider getting data for prefix_user_exercise in your frontend and update it using
$user_id = get_current_user_id(); // Get user id of logged in user (Bob).
update_user_meta( $user_id, 'prefix_user_exercise', '3/4 swing' );
In order to use a custom table to save additional data for a user, you will need the following code to get information.
global $wpdb;
$user_id = get_current_user_id();
$sql = "SELECT * FROM {$wpdb->prefix}my_table_name WHERE ID=%d";
$user_data = $wpdb->get_results( $wpdb->prepare( $sql, $user_id ) );