inconsistent number of columns in tables

### Bug

Try to convert table > html but on some pages columns data are missing, on the other pages they are available. As most LLMs I have tried this is a problem where a column has header but there is no data in it, so this is not detected as column . Then on another page this column has some data and is detected. So we got 2 tables with different columns count which is obiously wrong.

Solution would be force column names on model i.e 2 step detection - first headers and then having the list of names detect data.

### Steps to reproduce

export_to_html()

### Docling version

...

### Python version

python3.13

[

[klukomrun.pdf](https://github.com/user-attachments/files/19549664/klukomrun.pdf)

](url)