Are there any benefits for a person without diabetes to take a glucose tablet when eating a meal is not possible?

Not much: Glucose will provide some calories but no protein or other nutrients. If you can't sit down and have a balanced meal a good quality breakfast bar or energy bar might be a better choice. An apple of other fruit would be another consideration.

No; actually harmful: Glucose is sugar. Sugar is toxic. One should not take sugar unless one is hypoglycemic (low blood sugar). Our bodies do a great job of maintaining normal blood sugar levels even when fasting several days (we break down fats to form glycogen which is stored in the liver and easily converted to glucose). Skipping meals can be healthy! See http://tinyurl.com/ber748c and http://tinyurl.com/gqbkmou