This thesis addresses the challenge of the culturally dormant long tail in television archives. It argues that the issue lies not only in access, but also in the mismatch between a dynamic media and a static archival paradigm, which often overlooks the experiential value for the public, especially non-specialist and casual audiences. My research activates a fluid mode for archival practices by reframing television archives through a conceptual lens called Personal Memories of the Everyday, and unlocks new forms of resonance beyond traditional notions of their historical and cultural significance. This activation unfolds in two stages. First, the encoding stage transforms archival content into representations of memories made through watching using a novel computational pipeline. It puts forward a memory-based video representation through text-video joint embeddings, with the guidance of a phenomenology-focused meta-happening description. These embeddings aim to link sensory richness with nuanced human interpretation in a latent, open-ended form that resists static meaning. Second, the decoding stage reimagines the engagement with archives as mediated memory practices. To demonstrate the conceptual and computational propositions, two demonstrative interfaces were developed and evaluated with the archive of Radio Télévision Suisse (RTS) through the mechanism of emergent narrative and serendipitous discovery. As a result, users can form dynamic, universal, yet deeply personal connections with archival content, bridging and negotiating the private and the public, the present and the past, the embedded and the embodied. In culmination, this research lays the groundwork for a profound transformation in the future of television archives through computational mediation, reimagining archival engagement not as static retrieval but as an ongoing, inclusive, dialogical co-creation of meaning. It offers a tangible path forward for cultural heritage to evolve into vibrant, human-centred memory ecosystems, ensuring enduring relevance for our shared televisual past across time and culture.