I must buy my own lunch and dinner as do most private sector employees. There is no hostility, but it galls me to see the sense of entitlement in some of the Public sector employees, when we in the private sector are struggling to exist
Are you saying that in general you have to buy your own lunch and dinner, or specifically when sent away from your normal place of work for training or meetings?
My experience of the private sector is that employers of any substantial size (hitch is the only suitable comparison to Govt departments) generally operate the same or a substantially similar system of reimbursement to the civil service rules. The fact that the OP is a civil servant is a total red herring, except insofar as it clarifies what rules & regs his employer is supposed to be operating by.
In principle, if you have a normal place of work, and your employer obliges you to be somewhere else (regardless of public or private sector), it is entirely right and proper that you are not out of pocket as a result of that obligation.
In this instance, the employer are providing B&B accommodation, but the OP isn't in the position (as he would be at home) to do his normal thing in terms of lunch & dinner, so there is an additional imposition and cost on him, and the €33.61 reflects that. I think the rules were drawn up generations ago when the typical officer would be a family man with a wife and kids at home, so the household still costs the same to run whether you're there or not - the allowance was intended to cover the incremental costs.
Any private sector employer not operating some variant on the civil service scheme, and leaving their employees out of pocket, is quite frankly stingy and exploiting their workforce, but that shouldn't mean best practice should regress to their level.