You can link two tables using a dropdown column. With this column, you can show the column values of another table. In this way you can choose one of these values and create a link between the two tables.
Below you have a procedure on how to connect two sample tables: Customers and Maintenance. In the Customers table there is a Name column that we will use in Maintenance table. So make sure you have a Customers table in the database and table maintenance with its columns.
The two tables are linked, in Maintenance table is now possible to choose a customer from Customers table.
After linking two tables through a dropdown column you can use one or more derivated columns to automatically copy other values of other columns from source table. For example, you can copy also the address, the city and the email of a customer. Read more about the derivated column in support guide.