The purpose of this test data is to provide a regression mechanism as part of QDoc's end-to-end test, tst_generatedOutput, for an issue (QTBUG-70959) that was reported against QDoc's \keyword command. The issue, as experienced by the reporter of the bug, is that if the \keyword command isn't followed by a new command, or is the last command in a paragraph, the following paragraph is "eaten". That means the entire paragraph is understood by QDoc as keywords and included as html meta information instead of as part of the rendered output.
The bug report is at https://bugreports.qt.io/browse/QTBUG-70959. It refers to a change that bypassed the issue by moving the \keyword command, at https://codereview.qt-project.org/c/qt/qtdoc/+/242033/.