Both those numbers aren’t too bad, the 3.7 is slightly low but as you are diet only then that shouldn’t be a problem unless you begin to feel a bit wobbly etc. I often have numbers in the mid to high 3s before my meal. Also meters aren’t totally accurate so you could have been a tad higher. The 7.3 2 hrs after a meal is ok too, anything under 7.8 is considered fine but some like me prefer to be lower
But…
The important number you need to look at with those readings is the rise, they say a rise of no more than 2 is best, you had a rise of 3.5 so a bit over the 2. This information tells you that your body didn’t cope that well with the carbs you had, both lentils and rice are very high in carbs, maybe try reducing your portion of size or replace one of them with a lower carb protein.
Are you vegetarian? If not try replacing the lentils with any meat, chicken or fish and maybe reduce the size of your portion of rice and add some low carb veggies instead such as courgettes, green beans - anything grown above the ground, apart from sweetcorn is lower in carbs.
Edited to add some info
Edited by mod to remove quoted post