H²Table: Hierarchical Hypergraph-Enhanced Large Language Models for Complex Table Reasoning

Jia Ling, Yangfan Wang, Chen Tang, Haoming Tan, Yang Yang, Yi Guan, Jingchi Jiang


Abstract
Tables are ubiquitous across diverse domains, yet reasoning over them remains a significant challenge for modern large language models (LLMs). Current approaches typically linearize tables into sequences, inherently overlooking their intrinsic two-dimensional and hierarchical structure. To address this, we propose H2Table (Hierarchical Hypergraph-Enhanced Table Reasoning), a novel framework that represents complex tables as hierarchical nested hypergraphs. To process this representation, we design a tailored hypergraph encoder to facilitate message passing between hyperedges (headers) and nodes (cells), thereby perceiving the semantic entailment relationships between them within complex tables. Furthermore, we introduce a set of learnable query vectors acting as a lightweight bridge to extract representative structural embeddings from the encoder into the LLM. Experimental results demonstrate that our approach effectively handles complex table question answering tasks with hierarchical nested headers. Notably, on the HiTab dataset, H2Table achieves an average improvement of 22.88% over state-of-the-art baselines on highly complex tables with a nesting depth of four. Our code is available at: https://github.com/lila120/h2table.
Anthology ID:
2026.emnlp-main.325
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
7514–7525
Language:
URL:
https://aclanthology.org/2026.emnlp-main.325/
DOI:
Bibkey:
Cite (ACL):
Jia Ling, Yangfan Wang, Chen Tang, Haoming Tan, Yang Yang, Yi Guan, and Jingchi Jiang. 2026. H²Table: Hierarchical Hypergraph-Enhanced Large Language Models for Complex Table Reasoning. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 7514–7525, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
H²Table: Hierarchical Hypergraph-Enhanced Large Language Models for Complex Table Reasoning (Ling et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.325.pdf