Test.load() can be used to load Data from Static Resource in Salesforce Test Class. The Static Resource should contain a csv file.

1. Create a csv file with sample data. Example is available in https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_testing_load_data.htm.

2. Create a Static Resource with the .csv extension file created in Step 1.

3. Use Test.loadData() to use the records from the Static Resource.

Sample Apex Code:

@isTest
private class CSVTest {
    
    @TestSetup
    static void loadDataFromStaticResource() {
                
        List < sObject > listAccounts = Test.loadData(
            Account.SObjectType, 
            'accountData'
        );
        
    }
    
    @isTest    
    static void testAccountsFromStaticResource() {
        
        List < Account > listAccounts = [
            SELECT ID FROM Account
        ];
        Assert.isTrue(
            listAccounts.size() == 3, 
            'Expected 3 accounts'
        );
        
    }
    
}