Piece of Table: A Divide-and-Conquer Approach for Selecting Subtables in Table Question Answering

Wonjin Lee, Kyumin Kim, Sungjae Lee, Jihun Lee, Kwang In Kim


Abstract
Applying language models (LMs) to tables is challenging due to the mismatch between the two-dimensional structure of tables and the one-dimensional inputs expected by LMs. This mismatch forces linearization, making LMs particularly sensitive to irrelevant cells. Subtable selection mitigates this challenge by isolating question-relevant content prior to answer generation. However, existing approaches either rely on independent row or column selection, failing to capture cross-row and cross-column dependencies, or attempt global reasoning and face challenges similar to holistic table QA under noisy contexts. We propose *PieTa* (Piece of Table), a divide-and-conquer subtable selection framework that progressively aggregates locally selected evidence without requiring explicit global reasoning. *PieTa* uses an iterative, window-based multi-resolution process to construct compact subtables that capture global dependencies while limiting LM exposure to irrelevant content. Extensive experiments demonstrate that *PieTa* consistently outperforms prior subtable-based and holistic table QA approaches.
Anthology ID:
2026.acl-long.1460
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
31672–31688
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.1460/
DOI:
Bibkey:
Cite (ACL):
Wonjin Lee, Kyumin Kim, Sungjae Lee, Jihun Lee, and Kwang In Kim. 2026. Piece of Table: A Divide-and-Conquer Approach for Selecting Subtables in Table Question Answering. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 31672–31688, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Piece of Table: A Divide-and-Conquer Approach for Selecting Subtables in Table Question Answering (Lee et al., ACL 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.1460.pdf
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