Cross-lingual named entity recognition (NER) aims to build an NER model that generalizes to the low-resource target language with labeled data from the high-resource source language. Current state-of-the-art methods typically combine self-training mechanism with contrastive learning paradigm, in order to develop discriminative entity clusters for cross-lingual adaptation. Despite the promise, we identify that these methods neglect two key problems: distribution skewness and pseudo-label bias, leading to indistinguishable entity clusters with small margins. To this end, we propose a novel framework, MARAL, which optimizes an adaptively reweighted contrastive loss to handle the class skewness and theoretically guarantees the optimal feature arrangement with maximum margin. To further mitigate the adverse effects of unreliable pseudo-labels, MARAL integrates a progressive cross-lingual adaptation strategy, which first selects reliable samples as anchors and then refines the remaining unreliable ones. Extensive experiments demonstrate that MARAL significantly outperforms the current state-of-the-art methods on multiple benchmarks, e.g., +2.04% on the challenging MultiCoNER dataset.

With the rapid advancement of Large Language Models (LLMs), there is an increasing need for challenging benchmarks to evaluate their capabilities in handling complex tabular data. However, existing benchmarks are either based on outdated data setups or focus solely on simple, flat table structures. In this paper, we introduce **RealHiTBench**, a comprehensive benchmark designed to evaluate the performance of both LLMs and Multimodal LLMs (MLLMs) across a variety of input formats for complex tabular data, including LaTeX, HTML, and PNG. RealHiTBench also includes a diverse collection of tables with intricate structures, spanning a wide range of task types. Our experimental results, using **25** state-of-the-art LLMs, demonstrate that RealHiTBench is indeed a challenging benchmark. Moreover, we also develop TreeThinker, a tree-based agent that organizes hierarchical headers into a tree structure for enhanced tabular reasoning, validating the importance of improving LLMs’ perception of table hierarchies. We hope that our work will inspire further research on tabular data reasoning and the development of more robust models. The code and data are available at https://github.com/cspzyy/RealHiTBench.