Theoretically it should be possible to use another ‘back-end’ – but, I would guess that it would require so many changes (‘stored-procedures’, application hooks, etc.) – too big a job for so little utility since, I believe, the core market for TABBLES is organizational network installations, where SQL Server may already be deployed.

What particular problem are you having installing SQL Server?
Most times, if your Windows system is fairly typical, it installs easily, although you do have to make choices along the installation path that can seem confusing.
Have you ever installed a recent ver. of Visual Studio on this machine?
If so, SQL Server should already have prerequisite components installed.
I’d try again with the most recent ver. SQL EXPRESS 2014
“Express with Tools (SQLEXPRWT) ”
Remember to “enable Sql authentication mode” (mixed mode – both windows auth. and SQL auth.)