We study the problem of resource reservation and allocation (RRA), aiming to enable network operators (NOs) to effectively develop the coexistence of enhanced mobile broadband (eMBB) and ultra-reliable low-latency (URLLC) services by acquiring resources-such as spectrum, base stations (BSs), and transmit power of the BSs-from the infrastructure provider (InP). To do this, we quantitatively analyze the impact of spatial-temporal aspects of the network, including the spatial distributions of users and BSs, wireless channel conditions, and user traffic statistics, on resources required to support users' requirements using the meta distribution. Since spatial-temporal aspects operate on different time and space scales, we investigate a multi-timescale RRA (MT-RRA) scheme that facilitates collaboration between the InP and NOs to acquire resources through long-timescale RR (LT-RR) over the spatial distributions of users and user traffic statistics and medium-timescale RR (MT-RR) over wireless channel fadings. Subsequently, NOs allocate these resources to their eMBB and URLLC users in shorter timescales. To address these problems, an iterative decomposition method is proposed. The MT-RRA scheme can take advantage of the spatial-temporal aspects, flexibility of the MT-RR, and costeffectiveness of the LT-RR. Our simulation results demonstrate that the MT-RRA scheme can obtain 10% and 23% improvements in the average throughput of eMBB and URLLC users, respectively, regarding the link reliability of the eMBB and URLLC users in comparison with single-timescale RRA schemes.