You have to define a namespace and use it in your XPath expression:
$ xmlstarlet sel -N ns="http://schemas.microsoft.com/random/2006/objects" -t -v "//ns:table/ns:row/ns:field[4]/text()" test.xml
The command above uses -N ns="http://schemas.microsoft.com/random/2006/objects"
to declare a namespace named ns
that is set to the value of the default namespace in your XML file. Then the XPath expression is set so that this ns
prefix is used.