Depends, mmaped files are cached
try changing settings via nftables
net.netfilter.nf_conntrack_generic_timeout=60
net.netfilter.nf_conntrack_tcp_timeout_close_wait=30
net.netfilter.nf_conntrack_tcp_timeout_established=180
net.netfilter.nf_conntrack_tcp_timeout_fin_wait=30
net.netfilter.nf_conntrack_tcp_timeout_syn_recv=30
net.netfilter.nf_conntrack_tcp_timeout_syn_sent=60
net.netfilter.nf_conntrack_tcp_timeout_time_wait=30
net.netfilter.nf_conntrack_udp_timeout_stream=60
I have a router with 64 MB of RAM and it pulls out more than you have connected 
and it has never hung
a regular archer c20 drags a whole hotel and I have no idea how many devices are connected