Exception of type 'System.OutOfMemoryException' was thrown

Question

I am trying to read xml files and load the data to data base.
While reading and adding xml file to list of object.
I get 'System.OutOfMemoryException'.
I could have more than 6000000 xml files which I am not sure

my code:

foreach (var xml in xmlFiles)
{

try
{
XmlRootAttribute xRoot = new XmlRootAttribute
{
ElementName = "CASE",
IsNullable = true
};

XmlSerializer xs = new XmlSerializer(typeof(MyTable), xRoot);
MyTable cs = new MyTable();

using (var sr = new StreamReader(xml))
{
cs = (MyTable)xs.Deserialize(sr);
// cases.Add(cs);

LoadtToLocalDB(cs);

}

}
catch (Exception ex)
{

using (var writer = new StreamWriter(errorLog, false))
{
writer.WriteLine(xml);
writer.WriteLine(ex.Message);
writer.WriteLine("----------------------------------------------------------------------------------");
}
}
}