LoadFromDataReader

// lets connect to the sample database for some data
using (var sqlConn = new SQLiteConnection(connectionString))
{ 
    sqlConn.Open(); 
    using (var sqlCmd = new SQLiteCommand("select CompanyName, [Name], Email, c.Country, o.OrderId, orderdate, ordervalue, currency from Customer c inner join Orders o on c.CustomerId=o.CustomerId inner join SalesPerson s on o.salesPersonId = s.salesPersonId ORDER BY 1,2 desc", sqlConn)) 
    { 
        using (var sqlReader = sqlCmd.ExecuteReader())
        { 
            // Create a workbook and load the data from the IDataReader
            using(var package = new ExcelPackage())
            {
                var sheet = package.Workbook.Worksheets.Add("TestSheet");
                // The second argument specifies if we should print headers on the first row or not
                sheet.Cells["A1"].LoadFromDataReader(sqlReader, true);
            }
        } 
    } 
}

var filledRange = sheet.Cells["A1"].LoadFromDataReader(sqlReader, true, TableStyles.Dark1);
// if you want to get access to the created table:
var table = sheet.Tables.GetFromRange(filledRange);