Correct interpretation of a regression coefficient

Hi,

My question is not directly related to R, but rather a basic question
about statistics. I am hoping to receive valuable insights from the
expert statisticians in this group.

In some cases, when fitting a simple OLS regression, I obtain an
estimated beta coefficient that is very small—for example, 0.00034—yet
it still appears statistically significant based on the p-value.

I am trying to understand how to interpret such a result in practical
terms. From a magnitude perspective, such a small coefficient would
not be expected to meaningfully affect the predicted response value,
but statistically it is still considered significant.

I would greatly appreciate any insights or explanations regarding this
phenomenon.

Thanks for your time.